My DB coach and OL coach are the lowest-ratwed, so I try to train them whenever I can. The challenge is that those particular options don't always appear. So should I try and train another unit, boost a play, stop a play or focus on one specific play. (That one always seems like a waste of practice to me.)
Which brings up another question.
Should I train units which feature highly-rated scores, but whose coaches are below average? Or should I train units with low scores, but whose coaches are highly-rated?