Play bad. Usually, when i've taken over a bad/struggling team is when i've gotten the most transfers. From what i've experainced, the player relative to the program is pretty good, but they have to sit their first year after the transfer. So as texans said, if they haven't been red-shirted, or if they have, Frosh or Soph, special case for Juniors (not enough time to get them into the mix and playing without that red-shirt year still available)...i'll accept.
As far as position...not too sure. Seems like my most recent instance, I had about 4 RB, and got an 80 Soph (RS) transfer for SMU from Texas, which was about 3 points higher than my top guy. By the off season training, my SO(RS) had passed him up, so kinda pointless, but again, that's jsut on less scholorship you've gotta strugle to get placed...agian, were talking about pretty bad teams to recieve transfers, so recruiting budgets are pretty bad as well.