timing is everything in cricket regardless of your chosen discipline, in the case of fielding it is crucial to make stops, take catches and throw accurately, the best way to improve timeing is to practice for long periods and perfect the tecnique before taking it in to a match situation, the perfect technique for catching should incorperate these fundemntals...
1) watching the bat from the bat in to the hands
2) getting in to the correct position early with soft hands ready to collect the ball
3) bringing the ball in to the chest in a cushioning motion, imagine having your hands out infront of you and bringing them in to the chest as you recieve the ball to make sure it is safe and not going to pop out!
start off by just throwing a ball up and catching it, you can do this anywhere and it is a perfect way to improve timing your catch, gradually increase the height and when you can consistantly catch your highest throws you should have cracked it... and remeber, never be scared of the ball, a sting on the hands is easily better than a day of regret in the field as the bloke youve just drops goes on to smash 100s of runs!