The last update that added color coding to the player lists is the best way to decide where there's room for improvement right now.
My SR SF is maxed, and the assistant is still spamming me with "Ideas on Hubert Polk". I redshirted him as a FR and it's paid off:
whatifsports.com/hd/PlayerProfile/Ratings.aspx
I usually go 20 minutes on any player who has high potential in key areas - usually conditioning and footwork for the ATH/SPD/STA and the DEF. After that, it depends on where their potential is and where I see them fitting in.
On IQ, this is just me but I prefer higher IQ in defense. Since I allocate equal time to both OFF and DEF, though, the IQs seem to rise about evenly. I expect most of my players to be somewhere around a B IQ by the time they're sophs.