Isometrics work wonders for joint positioning, muscle activation, and performance. For example, do 3 sets of 3 reps with a 5 second isometric hold for the Kelso shrug during your warm-up.
The isometric holds will turn on the key players for performance. For the Kelso shrugs, that's the upper back. After the isometric holds, you'll notice increased upper back involvement during your training. When your upper back muscles work as they should, you'll be able to press more, throw better, and strike harder.
The method is simple, but very effective. Make the holds count though! You need to really contract the muscles, turn them ON, to reap the benefits.