HOLDING your sticks correctly will help you to control their motion and thus, control their sound!
LESS IS MORE!
The more you get out of the way of your mallets, the better tone you will get. The less you interfere with their motion, the more you disconnect yourself from the mallet head. This is true not only on timpani, but also on marimba and many other instruments. Often, you may use a very loose grip and let the mallets flop around in your hands!
PROPER GRIP