This achievement is awarded upon earning gold in each of the Rushing Drills on the Skills Trainer. Unfortunately, each drill requires you to be nearly perfect to earn gold, so you may become frustrated with the process (I know I was). Here are some tips and observations I came across in my journey.
General tips: Pick a low rated team (Raiders, Jaguars, Chargers, etc.), a team with a good running back and mobile QB (49ers, Seahawks, Washington, Panthers, or maybe the Eagles), and place the difficulty on Rookie. If you'd like, reduce the CPU sliders on defense to 0 (under settings in the Pause Menu). Also, I found it helpful to watch the tutorial videos and practice the moves a few times. It may take you a few tries to get a feel for the drill itself.
Acceleration Burst (9/10 for gold)
Use RT to sprint past the defense and score a touchdown. Sounds simple, but a rogue defender will most likely get you on one or two of your attempts. My suggestion is to let the blocks form in front of you. Your blockers will usually pick up everybody, making it easier to score. The outside runs are somewhat easier than the pitches, and running towards the right side seems to be more consistent than the left. Just use RT as soon as you get the ball and head for the endzone in a sort of diagonal angle. After a few attempts you'll get a general idea of how the A.I. reacts.
Precision Modifier (11/12 for gold)
The general idea is to use LT in combination with another face button/the right stick to pull off sick moves and make the linebacker look silly.
Important: READ THE DIRECTIONS GIVEN TO YOU. I would grow impatient and skip the text, then find myself failing because I didn't know what move to use. The one move that especially gave me trouble was the stiff arm. For some reason the game wouldn't register the correct move, even if the defender fell. The reason for this, I think, is because I didn't get the proper animation. You know you've done it correctly when the defender is sort of lifted off his feet and dropped to the ground WWE-style.
The other moves are pretty straight forward. The spin move (B), jukes (left/right on RS), and the rapid sprint (hold LT, then release it and hit RT) can be set up early. Lead the defender in one direction, then perform the move. The defender should be left in the dust. The truck move (up on RS) you perform just before the defender tackles you. The final 2 moves will be hurdle (LT+Y) and dive (LT+X).
The Option and Triple Option (9/10 for both)
Watch the videos for the general idea on how to run the option. It'll help with the following:
If you're having trouble reading the Dive Key Defender like I was, a neat trick I discovered was, just as the QB is handing the ball off, pause the game and look at the free defender. Pausing it makes it so much easier to read the defense and judge whether to hand off the ball or keep it. To hand it off, just keep the A button held down after hitting Resume. This same trick can be applied to the Pitch plays and the Triple Option Drill.
Oklahoma Offense (9/10 for gold)
The easiest of the drills, simply use all your shiny new spins and jukes to score 9 TDs. Or not. You can score pretty easily on Rookie.
EDIT: TheLastDon suggests that you use Adrian Peterson and truck over the defender. Haven't tried this myself, but if this drill is giving you trouble then try it.
I hope I've clarified some things and made it somewhat easier to earn this. If I didn't, or this solution can be improved in any way, comment and I'll add/fix what's needed.