Usually I play S and A with RH and T and B with left, if possible. So the soprano note is usually played by 3, 4, or 5, alto by 1 or 2. Bass typically 5 or 4, tenor 1, 2 or 3. Of course, you have to modify as you go, and sometimes do need to play the tenor with RH...best strategy, I think, is to look ahead -- and use the pedal!
To get a really full sound you can do this: play the bass in 8ves; RH plays the melody in 8ves, with middle fingers taking alto and tenor notes (tenor may be higher than alto when doing this). This is a really good exercise.