When one reaches, or even surpasses their limits against their opponents, they reach a state of comfort in their game play, so much so that they're able to move and hit at their most efficient. This opens up the opportunity for the brain to channel more thoughts beyond where to hit the shuttle next.
This state of mind is, in my opinion, the best time to perform trick shots - highly technical shots made with the purpose of misleading and delaying the opponent's reaction to the shuttle.
When you're facing a tough opponent, it's almost impossible to throw off a good trick shot. The stress of the moment, coupled with the brain dominating in fast decision making processes, make it very hard for the calculated and smooth execution of a trick shot.
Turning the situation around, if you're up against an opponent you're more comfortable with, even if they are of a higher level, your mind starts to wonder what else you can do. The state of mind is then more conducive for a higher level technique.
The above briefly states the nature of playing trick shots. Given the level of play some readers are used to, and for those aspiring to grow in technique, I will now attempt to explain some of the simpler trick shots I have managed to use with better success.
This is pretty basic, and involves turning of the racket head away to sent the shuttle in the other direction. The approach should be early and obvious - "I am going to hit the shuttle in this direction." When at the next moment, having given the opponent enough time to process the information, change the destination of the shuttle.
This move is pretty easy to pull off. All you need is to be able to out your racket head forward in one direction and then change the hit to the other desired one. The other two shots are variations of the direction change, and will require a little more practice.
The shot is made with less power than intended, although a large swing gives the impression of a harder hit. The best time to use this move is when you're being pushed to execute an underarm clear. The opponent will most likely expect a high and defensive clear for you to buy time.
This move is a test of control of the shuttle. The swing forward should be made at force and speed, and then taken away the moment before the racket head makes contact to perform a dipping net shot. Care has to be taken to place the shuttle as near to the net as possible, to have the cork on a downward trajectory so as to increase the distance between the shuttle and the opponent.
A variation of this technique is the backspin. Instead of releasing power from the shot, the momentum of the swing is transferred to the shuttle in the form of a slice to the bottom of the cork, like a backspin in a game of tennis. This produces a low-arching shot that can cut very close to teh net and dips quickly. Because of the low arch, the shuttle will most likely travel further than an outright pull-back.
So you've learnt how to change directions, and you've learnt to control the amount of force you put to the racket. It's now time to take things up a notch and perform what I call a double draw, or double motion. This involves moving the racket to take the shot, and pulling back the racket head before the hit, and then changing the direction of the shuttle.
This is a little more convincing than a regular direction change in that the player actually commits to a hit, increasing the level of deception and showmanship. The racket head will actually be traveling in the same direction as the shuttle after the draw, and that is one awesome thing to see executed well on the court.