As I thought about it, I realized I've developed my own preferences for binding and that maybe it would help you if you're still figuring out what you like and how to get your binding to place where you're happy with it. If you're looking for show quilt binding tips, this is not it. But if you want to be happy with secure and even machine binding, keep on reading!
First, I figured out years ago that I prefer two inch wide binding strips. I don't make it on the bias unless I have round corners, so straight grain is generally fine. Many tutorials use 2-1/2" wide strips, but I find this too wide. I will make a tutorial on making binding tape later, but for today, know that you need the circumference of your quilt plus 15". Most say 10-15" but I'm more comfortable with at least 15".
Once you have your binding, you'll need to prepare your quilt. There will have been some shifting, for lack of a better word, during quilting and the edges might not be as straight as they were. I have one quilter who trims the quilt after she quilts it, but I actually prefer it when they don't because I have to trim it again anyway. The most important part here is to make sure you don't have any spots where the batting is uncovered 1/4" or more from the edge. It's okay if there are spots where the top doesn't quite meet the edge, as long as it is within the seam allowance of the binding. Less important, but still something to pay attention to, is to make the quilt as square as possible. This is something I always struggle with, and even when I think I do a great job, the corners won't line up perfectly when I fold it, which is a telltale sign I missed the mark. However, this is honestly less important. The thing with folding is that you have multiple layers so getting it to line up isn't going to really happen anyway, and who really cares how it looks folded up?
To trim my quilt, I like to lay it out on the floor. I have a spot in my sewing room I usually use, next to the wall, but so I could have better lighting for pictures, I spread it out on my bathroom floor. You want a space with hard flooring and with a long enough space so you can have the full length you are trimming nice and flat. My space isn't wide enough to accommodate a completely flat quilt, and that's okay. I tend to drape the opposite edge on itself while I'm working. As long as you can spread the length you're working on flat, it's okay for the quilt to be rolled or folded on the opposite side. You can do this on a table or counter, but I choose to do it on the floor, for now. Maybe in 10-15 years I'll adjust.
I use an old 18"x24" mat for trimming. Please note I'm left handed, so my set up may look backwards to you. I start it at the bottom corner and cut a full length on my 24" ruler, and then I shift the mat forward. Make sure to resmooth the quilt as you go so it stays nice and flat and even. I like to work in lengths of about 18-20 inches, so that I can line my ruler up with the previous 4-5 inches or so that I've already cut.
Once you reach the corner, you can quickly cut the rest of the edge off, and then rotate the quilt and start with the next side. I rotate the quilt so I can line the bottom of the ruler up with the previously cut edge. This will help with keeping the quilt square, but it does assume that the first edge was cut as square as possible.
Once you've done all four sides, you're ready to start attaching your binding! You'll want to do this step when you're ready to actually bind. Some quilters will stitch a victory lap around the finished quilt, and that will help prevent any seams from coming unstitched at the edges, but I sometimes end up clipping some of that victory lap during trimming. Just handle it with care. It's not intensely fragile, but something to be aware of.
Traditionally, binding involves attaching the binding to the front of the quilt first. This is likely just a carryover from hand binding techniques, but it's still the way most recommend you start. I recently bound a minky backed quilt to the back first, and realized I should have been doing it this way all along! So here's a reassurance that you can bind anyway you see fit. I'm sharing my methods that I've liked, but find what works for you. The most important part is that your edges are securely bound.
You'll want to use a walking foot for binding if you have one. I don't use dual feed for this because I use my walking foot, but you could try dual feed if you prefer it. I use a 1/4" seam allowance when I bind and I find the 1/4" mark on my Bernina walking foot to be pretty great. I like to bind quilts right before I change my needle if it works out, and that's probably wrong, you should probably start with a fresh one, but binding really dulls needles so you'll want to change your needle after binding for sure.
If you're going to add a label to the binding, now is a great time to get that pinned into place. For this quilt, I added two labels. I usually use a white square folded in half corner to corner for a label with the quilt information like my name, quilt recipient if applicable, pattern designer, longarmer, and date completed. But I also opted for this quilt to add a premade label I got from a friend. I have a bunch of cute ones and I don't always remember to sew them in but I think they're fun. These just need to be caught in the seam allowance so pick your spot and pin it down.
Pick a side to start binding, and again, I start on the back, and I usually start so I'll hit the corner with the label first. I like to start on a long side if it's not square, and I start about 25 inches from the corner. I do this so I can bind most of the first side, and when I turn the final corner, I'm really close to being done. It's a mental trick. You also need to leave enough room so you can sew the two ends together and not be too close to the corner. Line up the raw edge of the binding with the raw edge of the quilt.
For this quilt, my binding is nice and wound up because I made double the amount I needed so I could use it for a quilt that is currently being quilted. It's nice if you keep it wound, but I usually just have a pile of binding next to me that often winds up on the floor. As you sew, you'll want to make sure that you're not pulling either the quilt or the binding. If you can feed them through the machine as evenly as possible, it will prevent wavy edges. I struggle massively with this. One trick I do is to make sure my table is cleaned off so there's room for my quilt. I also pause often to readjust.
When you get to the corner, you'll need to stop and backstitch about 1/4" inch away from the edge. If you're doing a wide SA because you're using wider strips, you'll need to stop the same width as your SA. A trick I learned a few years ago is that there is a horizontal line on the Bernina walking foot that is 1/4" away from the needle. It's really hard to see in photos, but it's just before the open part of the middle of the foot. I like to use my nail while the machine is stopped to see how close the edge is to those marks. Cut the threads and remove the quilt.
Turn the quilt so it's oriented for the next side. Bring the raw edge of the binding to the raw edge of the quilt. This next step might feel a bit like origami if you haven't done much binding before, you can absolutely do this. Make sure the edge of the binding is tight at the corner, meaning it turns the corner without excess fabric. This will create a triangle at the corner.
Hold the binding to the new edge with one hand and use your other hand to adjust this triangle so the fold is about a 90 degree angle. There should be a fold that lines up exactly with the edge you just sewed, and another fold underneath that lines up with the binding fold on the edge you will sew.
Start at the edge and backstitch and then sew the edge all the way down until you get to 1/4" before the edge and repeat the corner.
You'll do this for all four sides until you almost reach where you started. Once there's only about a 15 inch gap between where you are and where you started, stop and backstitch.
Cut the threads and remove your quilt. Lay your quilt edge where you're working on a flat surface and smooth it so you have a flat space to work. (Note that I have a lot of binding left because I'm going to use the same binding for my next quilt. Your end will be much shorter.)
If you left the selvage on your binding tape, cut that off now. Overlap the beginning and the end piece and smooth them so they're flat.
Open up the two ends of the binding and pin them together perpendicularly with right sides together being careful that they are not twisted. Sew the two pieces corner to corner. When you sew binding strips together, it's preferable to sew them together on the angle like this so you don't have a bulky seam on your binding. It's trickier to sew this seam with your walking foot but I usually do because I dislike changing feet so frequently. Once you have sewn it, check your work before you trim the corners. I have had to unpick more than once because I sewed on the wrong corners, because I managed to get it twisted, or just because I didn't sew very precisely. Checking is easy. Just do it.
Once you know you're binding is sewn together and it will lay flat well against the quilt, trim your corners and press the seam open. Refold the binding and give it another good press. Return to your machine and sew the remaining 15" of your binding down.
Return to your ironing board and press the binding away from the quilt. This helps so that the binding will be nice and flat on the back and helps make it easier to turn. You don't need to mess too much with the corners, just get the binding pressed well where it's already sewn.
Back to the sewing machine. Where you start is less important now that your binding is sewn all the way around, so pick a spot you like and get started. I do not use binding clips though some people do. I prefer to turn it as I go, working with about 4-6" at a time. I do not move my needle, and instead just eyeball it, making sure my binding is over far enough to just catch the edge. This way, it looks like top stitching.
Once you get to your first corner, you'll need to do some finessing. You can do this in reverse and I often will try it in reverse if I feel like the mitered edge doesn't look neat and tidy. But, I always start with pulling the edge of the next side up so that it will be underneath and then fold the side I'm sewing back down on top.
This should result in a nice crisp corner with a miter at about 90 degrees. If they are uneven, you can try again, making an effort to pull things more precisely, or you can try the reverse so that you pull the side you're working on over first and then bring up the bottom. Hold the corner tightly, a stiletto tool can be helpful but I usually just my finger, and once your stitches have just crossed where both fabrics meet, stop with the needle down, raise the presser foot, and rotate the quilt.
Lower the presser foot and resume sewing the next side. Continue all the way around until you reach where you started. If your corner is particularly bulky and not cooperating, you can do a little bit of surgery. This may happen if you had a seam end up on the corner or if your seam allowance was a tad heavy. VERY CAREFULLY, trim a very small amount of batting and backing making sure you don't accidentally clip the binding.
And that's it! Don't forget to fill out your label if you added one. I like to use a fine tip sharpie and then iron it when it's dry to set the ink.
