1) Tackling - I think everyone should be able to tackle, not just throw your body at some guys knees, lead with a shoulder, but wrap up and bring a dude down.
2) Rush - if you can't get to the QB, everything else just is guessing, and DL that can get to a QB, by and large can also stop the run.
3) Seal the edge - this requires OLBs who are fast, and who can find the ball. it also requires that CBs aren't taught to just run off 15 yards when the OLB has to crash down on the end of the line
4) pass coverage - we have been blessed with better than the average BYU secondary players, I like our new CBs and while they are raw, they are going to be good if they can be taught man coverage instead of prevent.