The most important aspect of playing badminton doubles is coordination with your partner.
Decide in advance what formation, or combination of formations, you will use – discuss this in terms of your overall strategy.
Choose between a side-by-side formation, an up-and-back formation, or a rotation formation.
Use the side-by-side formation when your team is in a defensive position. Both teammates stand at midcourt, following a lifted return that puts your opponents on the attack.
Use the up-and-back formation when you are on the attack. One teammate covers the front, trying to get the smash shot off a weak return; the other covers the backcourt, to handle clear shots.
Use a rotation formation to recover from difficult shots that drive you out of position. Each time one partner moves, the other adjusts on the diagonal.
Use verbal communication until you and your partner understand each other well. After playing for a while with the same partner, this should become less necessary.
Serve short serves, unless your opponent is expecting them. Deep serves invite an attack.
Rush the serve when returning serves. Attack.
Crouch low when the shuttle is behind you so that your partner can more easily hit over your head. Keep your eyes forward and trust your partner.