I use a regular steel thimble on my middle finger, though sometimes I will switch to a smaller one and put that on my ring finger--- depends on which feels right when I'm working. I only hand sew a few things-- labels to quilt back, for show quilts I hand sew the binding to the back, some embroidery stitches get sewn to the top before quilting, some embroidery stitches get sew to the top after quilting. If it's something that will be sewn to a quilt that's already sandwiched, then the thimble goes on my finger.
I have a bunch of thimbles, all came in batches of misc. sewing supplies that I got off eBay. I use whichever one fits whichever finger I want it on.
Rob