How are you supposed to use chess studies?

My credentials? Last year, I was merely a solid class F player, USCF, but after a 3-year tournament-hiatus, I exploded back onto the chess scene with a 50% victory rate against class D players. Now I am a solid class E player. You are welcome.

No, just applying what is known in the acquisition of expertise in other technical fields. It is a trade-off between "depth" and "breadth." In chess, many people argue that until one is rated 2100 (or whatever), you shouldn't study openings ("depth") because one still lacks "the basics" or "fundamentals" ("breadth") ... But then it is insane snobbery for a 2300 level player to say this to a 1900 player when a 2700 can easily wipe the board with his face every time using a dubious opening and claim that the 2300 also doesn't "understand chess", and of course Stockfish can do the same to the 2700. Studies are technical positions that have a single best move that you can learn a lot from, including the errors (play quickly through these also, don't ignore the error lines). There is no logical basis to treat studies any differently than you would any other position. The geometry, mathematics, and rules of chess are no different under these circumstances.
Thus, you can use them as a basis for pattern recognition, notably seemingly "quiet" positions. Alternatively, you can test your calculation, which would do less for your overall chess knowledge, but be a little more practical for actual games ... but only in the short term... The one who acquires more patterns and is more comfortable with the geometry and movement of chess pieces will eventually beat out the compulsive calculator. That is how Morphy could spend 25 minutes total in a game and his amateur opponents 11 hours and still lose. And I promise you, Morphy was a mad genius, but he wasn't literally 26 times smarter or that much a faster thinker than his opponents except in the microcosmic world of chess.

I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times. - Bruce Lee
If you cross paths with those who say they have inspected hundreds of studies, even taking several minutes for each one, do not be alarmed.
Instead, be wary of the individual who has become acquainted with only one, but for his entire life. This person has gotten to this point in time using this, and only this, maneuver.
Also, dannyhume, congratulations on your E-class achievement (1000-1199).