I made a T formation, with RB1 directly behind the QB, RB2 directly to his left, and TE1 directly to his right. I run some good sweeps to the right with that one, and then throw in a quick pitch to the left RB when my opponent starts playing the sweep right. If I have a mobile QB, I also like to run a bootleg sneak with all three guys lead blocking.
I have another formation ("Stacked") that is basically the Strong formation with another TE lined up between the TE1 and FB. I run a play called HB Read where I can either cut inside for 6-8 yards or try to hit the corner for a big gain. I have a passing play in the formation called "Crosses" where the TE1 runs a diagonal route to the other side of the formation and the TE2 offset behind him runs a diagonal route toward the sideline. If he's not open, the RB ran a short flat route to his side for some easy yards.
I have an all passing formation ("Firepower") that has the RB lined up a few yards directly behind a WR on the strong side about parallel with the shotgun QB. There's a play that has that RB taking a step back and cutting across the field behind the line. Anyone trying to guard him usually gets caught up in the traffic, and I can dump it to that RB once he clears and pick up some yards.
When he creating plays, I found Out routes work the best, so I suggest using those to an extent. I have another called Safety Attack where one WR tries to split the safeties and the other runs a deep out underneath him. That's usually good for about 15 yards.