One effective method of increasing intensity and busting platues, is to brake up the sets into clusters.
Lets say you normally do 3 sets of 12 reps for hypertrophy training. You are stuck at a certain weight. You like to increase intensity but keep the volume. What you can do is to brake up the sets into clusters of mini-sets with short rest intervals.
Do 3 reps, take a 10-15 second pause, do another 3 reps followed by a 10-15 second pause. Continue at this pace till you hit 12 reps and take 2-3 minutes rest. Repeat for another 2 sets.
Cluster sets are partically good for presses, and deadlift variations. Muscles involved in presses (chest, triceps and shoulders) contains a high amount of high threshold muscle fibers (type 2 fibers). To fully develop these muscle groups you need high intensity training (e.i. heavy weights). Same goes for strength development in deadlifts. Cluster sets is one way to increase intensity, and bust platues, still using the traditional set/rep scheme (e.i. 3 sets of 8-12 reps).
Pyramid type of training, or wave loading, can be combined with cluster sets. I often do wave-loading cluster sets of 7-5-3 reps for presses or 4-3-2-1 reps for deadlifts. The rest intervals are usually the time it takes to change the weights between the clusters.