Certainly use imperfective when specifying the manner in which the action should be performed.
Use perfective when asking for a simple action without it being really obvious next action.
There is also the important permission/denial pattern: use imperfective when NOT letting something.
MAY YOU DO IT? | Example |
---|---|
yes + imperf. | «Можно открыть окно?» — «Да, открывай». (I don't mind) |
yes + perf. | «Можно открыть окно?» — «Да, открой». (support) |
neg. + imperf. | Не открывай ничего. (do not allow) |
Curiously enough, imperfectives are absolutely polite for a few common motion and action verbs used when inviting people:
I guess they can be formally classified as obvious but you can also just memorize the verbs.
There is a distinction in Russian between putting things in a random or "lying flat" position and "setting" them into a vertical or upright position. The last one is important for things that by design are supposed to have a "working" orientation even if they are flat (a plate, a cup, a box, a bed, a laptop etc.)