I have always used 2 1/2" folded double and make sure it is full of batting. Before I sew the binding on I sew close to the edge all the way around the quilt then trim, leaving 1/4" batting & backing beyond the quilt. This ensures plenty to fill the binding. Just the way I was taught but it works for me.
My BFF trims batting & backing to the quilt edge .

2 1/2 is what I always use

On quilts, I use 2 1/2 but for table runneers and place mats 2 1/4.

This is what works for me too.

I do the same thing, except all my bindings are at least 1/2" (cut at 2½"), and usually 5/8" (cut at 3"). I've never been one to follow the recipe and I just think wider bindings have a better proportion to the size of functional quilts. I don't put bindings on my smaller art quilts; I finish those by the envelope method.

I like the 21/4 width. Works the best for me.

I too do 21/2 normally but have been known to do 3" -- it depends on the quilt pattern and how much loft the batting has.

I cut at 3.5", fold in half (I only do double chanel) and then stitch at .5"... so 3.5 folded is 1.75, stitched at .5 (with all raw edges together)... is 1.25 left to fold over again, now it's .75 left hanging over the edge..fold under and then there is a skimpy .25 left (the folds, seam and the depth of the edge all take up a bit) which i either blindstitch by hand or stitch in the ditch by machine for children's and donors' quilts.

This produces a standard .5" binding, which usually, but not always matches the last border. Any other width or color is purely a style choice... i still use .5" but most of my colorful children's quilts have all the scrap binding that i've used sewn together (on the slant, for eye pleasing) and then applied as normal, but letting all the colors just 'be' bright...

I started out using 2 1/4 inch binding; but now use 2 1/2 inch because I can cut that faster.