Ignore Luis Vega. The best thumb tip for stuff like that are the non rubber ones. Thumb tip for switching stuff like that are the hard plastic ones. They work the best. The rubber ones create friction; therefore, it is hard to slide stuff around. The most important thing is that make sure that you get the thumb tip that is bigger than your thumb, so you can fit your thumb in it while it stuffed.
Magically Yours
Tricky Devil
I don't think this is exposure. If it is, tell me how to delete this thread.