get 2 stools or chairs, put them on each side of urself then have shuttles on one stool and quickly put them on the other stool one by one. you have to be at the centre of the two stools or else there is no point in this drill. and also, you must be twisting your waist because that is the point of this drill.
I'm not convinced that twisting your waist quickly from side to side is a desirable thing in a training exercise.
What I do at home: - jumping rope - shadow swings (I kneel for overhead shots) - dumbbells, medicine ball - practice strokes and deception in front of a mirror (if I can fool myself, I can fool everyone else hehe) - abs, squats - swatting flies with a 160g practice racket (I'm actually quite good at this)
Very nice idea, I've done this before too. What I also do is.. I mark a point on a wall at about the height of the net, and practise my short serves and net shots against it ( with a plastic shuttle ofcourse ).
If by practicing against the wall you mean practicing drives or smash returns, my bedroom walls are far too small and irregular for this. I have broken the odd glass pane and picture frame here and there while practicing net pushes, and that's enough. jhirata's suggestion of practicing serves sounds good, I wonder though how do you make sure that you are not serving too long or too short? You may consistently hit the same point on the wall, but a different overall trajectory is going to make a big difference.... Maybe you should buy a sofa which is exactly 1.55m high and practice hitting a spot on the other side.
Measure 5 feet from the floor up the wall and tape an 8x10 piece of paper (landscape orientation) at that spot. Now measure 6 feet away from the wall and mark that spot as the "service line". Try to hit the center of the paper when you serve.
The best is keep running & keep practicing yr footwork run fast n slow do more footwork it really help alot play hit the shuttle in the wall, c how fast u can retrive the shuttle back. This is to train yr speed & reaction. But the best is do more footwork & running...