Warne, Bedi, Kumble, Muralitharan: The techniques of spin are as varied as the men who mastered it. However great spinners also have many things in common. If you can understand and copy these methods you can improve your own skill as a spinner.

1. Action. Spinners actions vary greatly but all great spinners have an action they can rely on. For most this will be side on to generate more spin. England off spinner Ray Illingworth likens his action to a cartwheel turning forward in a straight line. Practice with and without a batsman until it is automatic.
2. Control. A good spinner should be able to use his action to put the ball in roughly the same place every time. Terry Jenner, Shane Warne's coach, often talks about leg spinners being able to bowl the stock leg break at will before even attempting any variations. This is no different for the orthodox spinner. At club level you will always get wickets simply by tying batsmen down.
3. Mind Reading. Illingworth also talks about having a sense with certain batsmen. Just by looking at their stance or the way they play early in their innings can tell you a lot about how to set your field and what line to bowl. Keep trying to read the batsman, get into his head and try and think what he is about to attempt.
4. Bluff. Warne was the master of mind games at the top level. Many times I have sat watching England batsman get behind the ball with a textbook forward defensive only for Warne to treat it like he had almost bowled the man. And I believed him too. That's not to suggest you should resort to histrionics, but a well placed fielder or comment can out of even the most steely.

Other important factors in being a successful spinner include control of flight and variations. Without mastering the basics of action, control, mind reading and bluff you can forget about them. It's all about keeping it simple.