The best way to get to the qb is to use a DE. I've never been able to have success while starting as a DT, even with the almighty Suh. When controlling the DE, dont mess around with spin and swim moves, just outrun the offensive lineman and sack the qb. Even if the OL is decent, you should acquire atleast 4 sacks per game AND if you are playing online, more than that.
Online offense, scrambling/dual threat qbs are the way to go. The ability to run out of a passing play really keeps your opponent guessing.