Curious how people do this
Easiest is just to mentally take note of things that have been costing you strokes and working on them.
I've seen and currently use the Short Game / Long Game Handicaps to split it into those two areas.
Lately I've been going all OCD on it and breaking it into 6 areas: Tee Shots, Putting, Iron Accuracy, Iron Ball Striking, Club Selection and Chipping/Pitching. I'll go back through a round and attribute each dropped stroke to one category and then see if one particular area stands out over several rounds. For example the last couple rounds my Iron Accuracy and Ball Striking has cost me the most strokes (push/pull or hook, thin or fat etc) so tonight I headed to the range and focused on those two things the most.
Of course all these areas can always get better but I am trying to keep everything moving steadily in the right direction and don't want one particular area to get way out of whack (e.g. my game is great but I just can't putt or I just can't get off the tee in good shape etc).