The Stoyko Exercise or The Twenty Minute Exercise as Heisman calls it is interesting and useful. The idea is simply to deeply analyze any foggy position for twenty minutes. The inventor himself claims to have gained 100 points every time he did the exercise. Should that be 10% true, then I am a happy patzer!
So, I picked a Capablanca game almost at random and started at a random move. The position looked "obvious" and Mr Fritz agreed that I indeed found the best move. Mr Capablanca did not(!) but he on the other hand found the proper continuation.
Ergo: I suggest that you try the exercise for yourself. Al you need is a print-out which can be half hidden at your messy office desk allowing you to practice chess while pretending to be productive (from your boss' perspective)
I will take advantage of the sad fact that I have not studied the Classic games very well. So, I will probably pick the games/positions from the New York 1924 Tournament and hopefully learn something from Mr Alekhine's annotations.