Advanced bughouse tips
These tips are for more advanced players who are already familiar with the basic principles of bughouse.
Sitting vs. Moving
In time, you can learn a lot of opening theory, offensive bughouse patterns, and defensive bughouse patterns, but all of that still won’t get you too far. The most difficult part of this game is to know when to sit and when to move. Can you see the dilemma? You need to play really quickly in order to be uptime but you need to be uptime so you can sit for pieces that will hurt your opponent. 
Generally, there are two type of bughouse players: the chess players and those who suck hard at chess. The chess players can play blitz well - they play quickly without losing material, do decent moves, gain uptime, etc., but when they face an experienced bugger they still lose pretty quickly. Why is that? The reason is that these strong chess players don't know when to stop and sit for pieces.
On the other hand, those who are bad at chess usually sit way too much and try to play mostly with piece drops. Therefore, depending on what’s happening on the other board, both types of players could face huge problems. Indeed, the elite bughouse players strike a balance between these two styles - you need to learn when to sit and when to move!
Openings and Sitting
Let’s talk about the opening phase. At very high levels of play, openings are mostly premoved, but at all other levels, it's perfectly fine to sit a few seconds for a pawn which will basically win the opening. Let’s say later on you are 10 seconds up. Start using those extra seconds any chance you have. Sit for small advantages. This is the time to make your position really much better. After your uptime is gone keep blitzing several moves again; it will be much easier now. Once you have a more dominant position, you will gain uptime much more easily because your opponent won't be able to play that quickly without dying. Now, when you do gain another several seconds, use them the first time the opportunity arises. A good bughouse game is one with a lot of sits.
Remember: UPTIME IS USELESS UNLESS YOU (CAN) ACTUALLY USE IT!
Flow Control
Another very important aspect of bughouse is the flow control; it is very important to manage the pieces you have in hand. Generally, you should keep dropping the pieces you have in hand; you don't want to find yourself with a hand full of pieces as you won't have time to use them. Hence, when you trade pieces, don't trade too much at a time unless your partner has a lethal attack. You also don't want to keep him empty-handed, so generally the best flow is light but consistent.
You also must learn to protect your partner, which means you can sit (even if he or she didn't tell you to do so) if you see that a certain piece is going to hurt him or her. Take a quick look at his or her board: if you see that your partner has castled his or her king, for example, don't trade queens or your partner will get mated. Indeed, you shouldn’t wait for your partner to ask for a piece – you need to have an idea of what is happening on your partner’s board and feed him or her with material good for him or her and bad for his or her opponent.
In fact, in order to do so, you need to maintain control of the game. Whoever controls the game controls the flow. Whoever controls the flow is going to win.
Finally, I am going to leave you with one myth buster: bishops are better than knights in bughouse. There is no better piece for control than the bishop.
