No one can definately tell you a tactical shot position that you need to spend more time.Dont worry about missing tactics much. Better planning and better positional evaluation is more important than tactics, There are many ways you can win a game without doing tactics(taking risks). ( Even stockfish failed many tactical shots in tactical test suits).
With more experience, your decision about guessing tactical shots will be more and more acurate. It is called time management, where experience player will likely spend more time in more important positions.
If I play bullet, I usually decide in 3 tactical shots per game, average about 10 secs per move. In positional pushes moves, I spend half sec per move or 1 sec per move.
Lately I'm practising tactics a lot and managed to get my rating into around the 2050 zone which is decent in my opinion meaning i am not particularly weak in that area. However, my blitz rating stays low because I am looking for tactics in every position which instead calls for a strong plan.
Has anybody else faced this kind of dilemma. I knew a coach who suggested that the best way to improve your game is to go over entire games of masters. Maybe that's what I should do.
How did you improve in this area?