I've gotten decent at trills using fingers 2 and 3 (RH), but with my thumb and middle or index it feels very strange.
I don't have a teacher currently so I can't really get feedback on my technique. Anyway, should the motion come mainly from mainly depressing the fingers into the keys or with a combination of rotating the wrist slightly? Neither way really feels comfortable.
Also, I'm keeping my fingers touching the keys at all times. But raising them slightly after each note actually makes it easier to get more power and a little more speed, I assume it's best to keep them touching though for economy of motion?