I don’t know if it’s a tactile sensation thing or not, but I often tug on the tops of my ears - both hands - when I’m thinking.
At an office I once had we kept some phone books stacked on their sides on top of a file cabinet, at head height for my partner. She liked to lean up against the file cabinet and blow into the pages of the top phone book, so that the ruffling pages would tickle her lips. Sometimes I think she did that just to titillate me.