Not only does a thimble protect your finger from pokes, it is a useful tool to push the needle. This prevents having to grip the needle too tightly with the thumb and forefinger, which reduces fatigue and makes neater stitches.
The thimble I like to use has a flat top with a small edge to hold the needle in place when pushing through thicker fabrics or layers of a quilt. It has circular indentations on the tip and also has indentations on the side. You can also push with the side of the thimble. I wear the thimble on my middle finger.
I guide the needle into the fabric with my thumb and forefinger, then use the thimble to push the end into and through the fabric as far as possible. Then I pull the thread through the fabric using my thumb and forefinger.
Here's a picture of how the thimble looks pushing the needle through. Normally, I do it all in one motion.
A thimble is something you have to get used to wearing and using. But once you do, you will find it an invaluable tool. Make sure you get one that fits your finger - snugly enough so it does not fall off but not so tight as to be uncomfortable. There are all sorts of thimbles designed for people with long nails, or out of silicone. Find one that's your favorite and learn to use it! You'll be glad you did.
Do you use a thimble?