Backhand serves are better to control like with netting etc backhand has more control over forehand just like taking smash, but the downside is it requires wrist power to do a high serve and you must have a high level of control and "feel". Forehand serves are more suitable performing a slice-serve because its harder to commit a foul than backhand. Backhand is more easier to commit a foul if you try to add spin instead of just performing a normal backhand serve without any fancy stuff. Forehand is more easier to spot foul and easily recognize and you can change the habit easily.
Forehand serves can be short, high, or drive. They are now exclusively used only in singles. Very high and deep serves, used in singles, can only be done with forehand. Backhand serves are either of the short type of the flick serve. Other than the very high singles serve, in which the forehand serve is better, all the other serves are more effective with the backhand. The reason is that the backhand short serve has a shorter flight path, thus reducing the time for the receiver to get to it, very important in doubles play. The backhand flick is executed in the same way as the backhand short serve and is therefore more deceptive. Backhand flicks in doubles is more difficult to execute well than many players think. It needs a pronated arm/wrist and its direction in its alignment with serving shoulder is vital otherwise it lacks deception, length, and will often go to the sidelines. To ensure deception with backhand serves, use a flick-like serve for both the short serve and the flick serve.
As taneepak mentioned, the biggest differences are: A high serve can only be played with a forehand action For doubles, all the top players use a backhand serve Beginners usually find the flick serve easier on the forehand than on the backhand, and for that reason many stick with the forehand serve. I do recommend learning a backhand serve for doubles, however: the backhand low serve makes it easier to serve accurately, and your opponent has slightly less time to react. The wide serves, both low and flick, are generally also easier on the forehand. In particular, the backhand wide serve to your left (as a right-hander) can be difficult (although some techniques are harder than others). Note that drive serves can be played effectively using a backhand action too. See my serving guide for more information.
Since I started playing badminton, I always used my backhand for serving after watching several pro's perform the serve that way. At start I thought it was kind of a fancy serve only the pro players used. Now its so much more comfortable than a forehand serve, I feel less control over the shuttle using forehand and I fell better using backhand despite the fact that I play singles in competition.
I've been using a forehand serve when I started playing. About a year ago my coach recommended using a backhand serve. It didn't go very wel in the beginning. But my serve has improved a lot since then and I now use is all the time in doubles. I still use a forehand serve in singles, because I can't reach the back of the court very well with my backhand.
Almost always backhand but will do an intentional forehand serve/lift near the ceiling (repeatedly, doesn't matter losing a few as long as I can get them in the end.)...buying time to recover.
