The only reason an error occurs is because of a poor mental game. Club Matches Shoot only the ones that you think will help you improve. Don't waste your valuable time on poor matches, spend it practicing instead. Shoot to win all of them. You have to pay attention and focus just like the world title is on the line.
Every shot has to count.
If you are screwing around not paying attention in a club match, you are going to screw around in a major match and it will cost you money. Major Matches Shoot every one that you can. I would set a minimum at fifteen a year if you want to be a serious competitor. This match experience will add up fast. You will learn what it takes to be competitive on a national level.