Keep the ball Up!
There are different type of balls with special behaviour. You can try the normal plastic ball. It is a nice ball but sometimes a knife shows up and gets your ball down.
You can also try the fluffy cat! It is cute and there is no knife! The cat is very heavy so you have a better control over it.
Also try the crying baby and the little crow sometime. Crying baby gets Bottle to grow up! Little crow gets feather and you will have better control over it.
You get more scores if perform combo. You can perform the combo with tapping the ball without hitting the floor or wall. So avoid the wall and the floor to get score.
If you perform a combo that is a multiple of five you get additional 2 seconds. Also try different night field. In night field there is no wind so you have a better performance surely!