Playing alto 25 months
I read somewhere, "practice what ails you". Working on what you find hard is a huge key to progress. I also remember my improv teacher always telling us, "Everything is difficult until you master it". That is a good way to measure progress when the day comes that the hard thing is not so hard anymore.For a subjective appraisal (meaning your opinion of how you're doing), I find picking a "thing" that is hard and working on it a little each day helps.