Once you have oiled your new cricket bat you need to spend some time conditioning it before using it in a competitive environment. This is done by the process of knocking it in.
Ideally you should knock in any new cricket bat for at least six hours, yes it's a lot but it will help condition your bat for heavy usage without damaging it.
You should also knock-in your new cricket bat even if it comes advertised as 'ready to play', as it still won't be ready for the full force of a hard new cricket ball, especially if you catch an edge or the ball hits the toe.
I've seen players go out on to the square with a brand new cricket bat, which hadn't been knocked in. In the first over he dug out a Yorker, which resulted in a 'fatal' crack in the toe of the bat. If it had been knocked in properly it's unlikely this would have ever happened. If you don't knock in your bat you could literally be 'throwing £200 down the pan'.
To knock in your bat I highly recommend you use an old high quality cricket ball.
Begin gently by tapping the bat, particularly focusing in on the edges, as these are a very vulnerable part of the bat and by the end you want the edges to be almost slightly rounded. Graham Thorpe pulls a short delivery away through the on-side Spend 2-3 hours doing this stage of knocking in the bat, making sure you cover all of the face of the bat, excluding the splice area. Don't knock-in the back of the cricket bat.
After you have done this gradually increase the force with which you hit the bat, making sure you systematically cover all of the face of the bat. By the end you should be hitting the bat with full force to simulate the impact of a real cricket ball.
When you have finished knocking in the bat, you should first progress to using the bat for out field practice and then in the nets against an old used high quality cricket ball, especially avoid 'bat breaker' cricket balls, you know the ones, cheap, hard and usually shiny. If your bat is going to break or split it's these balls that'll do the damage.
Once you've played the bat in for a few hours in the nets it'll be ready to take out on to the square.
It's a tedious process but well worth the time and effort for the results you'll get for your hard work. Its worth mentioning that some sports shops may offer a knocking in service for a small fee. Personally I like to do it myself to see how the bat progresses as it becomes more knocked in.