Try plyometric exercises. These sorts of exercises will help you enhance your fast twitch muscles, stimulating greater muscle development. Like ballistic moves, plyometrics require acceleration. For instance, when doing plyometric push-ups, you let your hands jump off the floor and explode as high as you can. It is OK to take a few short-cuts when weight lifting. You can utilize a small bit of body weight if you need to squeeze out a few extra repetitions so that your workout is maximized. But do not make that an excuse to cheat on all of your reps! Keep your rep speed under control. Keep in mind that if you compromise your form, you will run the risk of injury. Some muscle groups are harder to bulk up than others. To help speed up the slow-growing groups, try a fill set. A small set that uses the muscle group necessary two to three days after another group was worked will do the trick.