One thing is for sure, you cannot do the same thing over and over again, your body will adapt and you will not continue building muscle at the same rate, these tricks however may help keep your muscles from getting used to the workload any time soon:
The king of all sets, if there is one technique I recommend you use it is definitely this one. I have busted through many plateaus with this one and I'm sure everyone else can to. Some people believe drop sets lead to over training, but I am a strong believer in the fact that muscles must be worked hard when you do work them, to grow. Only do them (each muscle) once per week, but really kill them when you do them.
What drop sets are, is continuing your reps even after you can no longer lift your current weight, but quickly switching to a lighter weight. So for example which do barbell curls of 80 pounds, when you become to tired to continue with that weight, you strip off a 10-pound plate from each side and immediately go again using 60 pounds. Until you can't do that anymore. And some people (myself included) drop down one more time and do it again. Actually my routine looks like this:
1st Set: 80lbs No drop set
2nd Set: 80lbs 1 Drop down to 60lbs
3rd Set: 80lbs Drop to 60lbs, Drop to 40lbs*
* Or lighter to reach my goal of around 3-5 reps at each weight
This gives a pump like I can't get from anything else, I also use this method for any exercise where I can easily drop my weight. I would not recommend Drop setting every exercise of your workout as that will most likely lead to over training. I usually begin my workout with regular sets, and the last few exercises are drop setted.
If drop sets are king then Pre-exhausting is definitely the Queen of the game. Many time, especially with muscles like chest which require the help of many other muscles to work, those other "helping" muscles get tired before the larger one that you are actually trying to work, making your attempt a waste of time as far as your larger muscle is concerned.
Pre-exhausting is the art of tiring the main muscle (from here on in I will refer to the Chest as that main muscle) with an isolation exercise such as dumbbell flies, then moving on to a heavier exercise like dumbbell presses when the chest is already tired so it will fail before the supporting muscles, in this case that would be the triceps and shoulders.
I almost always start off my chest workout with Dumbbell flyes, 3 sets to failure, by then my chest is already burning, by the time I get to the presses my chest fails long before my shoulders, which is the muscle that would normally give out first if I was doing presses first. The problem with pre-exhausting I think is the ego thing.
People love to lift heavy, no one wants to push their flat bench to the end of the workout when they will have to drop many pounds off the weight. Guess what? No one cares what you press! Get over it. What people do care about is how your chest looks at the beach, and it's going to look like crap if you don't get over this bench press thing. Make sure you work your muscles right, don't worry about the weight.
Not a personally favorite of mine, but I will talk about it none-the-less. Supersets seem to work in the same manner as Pre-exhausting if you super set the same body part. The idea is to do your regular sets, but in between doing those sets, you do a whole new exercise. It would be difficult as you would already be very tired from your first exercise, which is why most people superset different body parts. Biceps & Triceps, Chest & Back seem to be popular.
So you do your barbell curl for biceps, and then immediately go into skull crushers. Convient for me as I use the same weight for each. This is a good routine and your can complete two body parts in the time it would normally take to do one, as your rest time for one muscle is being used to do another. There seems to be some discussion however about whether or not this is a good idea as you are tired after doing your first exercise and may not be able to do 100% for the second. I would not recommend Super Setting all your workouts unless you must (very pressed for time). However it is a great system for when you are in a killer hurry.
The rest pause technique is great in achieving that unbearable burn people sometimes have a hard time getting. The idea is simple, at the end of your set, you hold the weight, either locked out in some cases or just resting on the machine, until you have enough energy to pump out a few more reps. With the chest for example, you would bench press until you could just bring the bar back to the top.
Then you could lockout your arms and catch your breath and let your arms stabilize (as mine tend to shake uncontrollably at the end of a set for chest) pause there several seconds until you recover and do another rep, pause and continue doing this until you just can't do it anymore. In terms of great technique's for building muscle, I believe this one takes a very close second, right behind drop setting, as it is a very close relative to the idea.
Let me explain the idea here first, the idea is to increase your weight as you become increasing tired. Triceps pushdowns on cables for example, you do a pushdown for 10 plates. In your next set, you pushdown 13 plates, and in your final set you pushdown 15 plates.
Increasing the weight each time. I use this method myself because I feel I need to. As I progess through my exercises and my muscles warm up I can always do heavier weight later on.
So pyramiding just happens to be necessary for me to stay in my 6-12 rep range. People ask me if they should do it, I don't see any usefulness of it if you don't feel comfortable doing it. There has been some discussion as to whether or not there is any point, and there seems to be a grey area.
I say do it if you can handle it, but don't push yourself into weights you can't handle. Use the other techniques listed about first anyway, they are much better.
These techniques are the best of the best. They have been around and will stay around for some time because they work. I don't recommend you do any of them all the time (prexhausting may be the exception) and I'd stick to one technique a workout. Drop set one day, and super set another. Throwing these techniques in your workout schedule regularly will keep your muscles wondering what is coming next, which means they'll be growing for a long time yet.