I think your biggest "problem" is using too wide a strip of fabric for the binding. It gives you too much to fold over.
If you used a 2.5" strip, try it with a 2" strip folded--That is what works best for me. For a beginner, you might want to try a 2 1/4" inch strip first. There is no hard and fast rule on how wide to make the binding strip--experiment until you find the width that works best for you.

Well, it depends on how you want to finish your binding.
If you stitching it with decorative stitches (like in your picture) you were right to sew it to the back first. If you want to do a hidden (stitching in ditch) row of stitching you would reverse and sew binding to front first. Fold it to the back but sew it from the front side , stitching in the seam line. I find I have to pin my binding down when I do it this way so I'm sure to catch the back side all the way.
Some people glue it down with Elmer's school washable glue, then stitch. Keep practicing!

See we learn something new every day. I am a self taught quilter and I was machine sewing my binding on so different then everyone on here it seems like. I line my binding up on the front and back...and just sew once. So I only have to sew around the quilt once and the front and back sew lines are the same. So no SID or hand sewing for me.

I use a 2.5 inch width binding, which gives me a 3/4 inch binding once sewn. Sew on back using 3/4 inch seam. Fold to front. Fold under & pin in place using the thread line as a guide. Folded edge should be just over the thread line. Then I sew usually @ 1/8 inch, which will show the same on the back. When I do corners I sew to seam line, flip/fold it, tuck it in using a stilletto, pin & sew around the corner.

I can put a nice binding on a large quilt, but have failed miserably on a tiny pot holder; go figure!

I've never mastered doing this...hope you get it to work well for you. I've gotten to where if I'm going to machine apply the binding, I just use a decorative stitch on the face of the binding (and that will hit both the front and back).

I cut my binding 2 and 1/2 inches, fold it in half , iron it and then sew it on the front fold it to the back. I always hand sew my binding with a hidden stitch.

It looks as if your binding was too wide. For instance, the back binding should have been moved over more and then sewn down. That way when the binding is rolled over to the front, the binding edges meet.

Sandy

I tried this the way Leah Day does it, and I just didn't like the results. I'm back to hand sewing the second side.

We did pocket potholders in class last year, and we pinned the binding on through all layers and sewed it together all in one stitch. I used a decorative stitch but it is hard to see in pic.

Also attached is another pot holder using the same technique.