There is some really terrible advice on this - I can't quite believe some of the commentary.
If you aren't timing the ball this is for two reasons, part of it is down to your form and the second part is down to how much time you have spent at the crease, two things that are inextricably linked.
So firstly if you aren't timing the ball well, you are probably going for too many shots too early in your innings and trying to hit the ball to hard. The answer is simply to grind it out, get some singles, get off strike and get used to batting again. It takes about 20 mins or more of batting to really get your eye in and to get used to the pace of a pitch - which is usually 6-8 overs. As a rule of thumb then, on that basis, don't go for too many shots too early unless it is a rank bad ball. I appreciate if you are playing a 20 over slog fest, this isn't that helpful - but playing 50 over league cricket or a Sunday game take the time out, you will reap the benefits later on.
If the pitch is hard and fast you can typically go for your shots a bit earlier as the bounce will be truer, but if you are playing on a pudding then it will take you longer and the crucial thing is not to go hard at the ball early. If you are on a tennis ball bouncing pitch, then take the "on the up drive" and put it firmly in the locker for the day. Your scoring shots are more likely to be the pull for anything short and other back foot shots, unless the ball is really over pitched.
Another tip I use is early on to hold the bat only very gently with my bottom hand early on, to concentrate on hitting the ball along the ground.
Failing that buy a new super pinging pro bat for £700 which guarantees you a boundary even with your forward defencive shots.