I can’t exactly attest to the best way now, but back when I first played (seasons 11-15 or so), I usually did the combine, and then assessed based on how many 18 y/o were in the bottom two (1-2 balls pre-scouting), and/or how many of my preferred height (I.E. if training guards, how many <6’5”? If bigs, how many >6’10”?) and if there were enough chances for my liking I ran Group demonstration. If not, I would focus my attention on 18y/o of preferred height only, and only second scout on 4+ balls skill players as long as sample game didn’t show ridiculous numbers of fouls (ie: I usually shoot for <2 fouls per 15min on the court).
I’ve been able to make things work out with 2 points per week purchased using that strategy, but it doesn’t always go my way- and with the 19y/o having the chance to be so much better now than back then (skills up to 9 instead of capping at 8, for example), I’m more tempted to scout the 19s, so I’d say combine + groups are more ideal now than before, and unlocking potentials on 5balls players from that group?