I made myself a leather thimble and I like it so much more than any store-bought one. I have long nails, and it works great with them.
This is a no-sew project, and if you have a scrap of fairly heavy leather, you'll have yourself a thimble in no time.
Simply cut the leather in the shape of an "H". The crossbar on the H is the part that wraps around, and covers the pad of your finger [approx. 1" by 1"]. The 2 sidebars of the H are 4 skinny strips [1/8 to 1/4" wide by 3 or 4" long] that you'll tie together to make it fit your finger. Two will tie at the back and two will tie at the front. You'll know they are tied correctly when the thimble will stay on, yet it's loose enough to take off. When you've got it just right, and tightly knotted, trim any excess length of the strips off.
This will go faster if you have some help to do the tying. I had to do it by myself...thank goodness for teeth, hehe.