I use the cheapie metal thimble with the depression in the top. I have several kinds but am accustomed to this one.
Made by Dritz. I learned also to use a thimble under neith the quilt. For that one, I get an old metal thimble that is rather smooth around the top edge and pound the top flat. I get them in for pennies at an antique mall. The underside thimble need to be rather smooth around the top edge for the needle point to slide off. I don't believe it dulls the needle.