Get a Tip on the Grip
One very important part of bowling overlooked is the grip. Two areas we will discuss is the fit of the ball and getting a better "feel" of the ball. This is such an important area especially to women because women do not always have the gripping strength to hold onto the ball. It is much easier to swing a 16 lb. ball that fits properly than a 12 lb. ball that does not.
Getting your bowling ball drilled by a pro shop is one of the best investments that you can make. You can be assured that you will most likely get a much better fit or "grip" by going to a professional than anywhere else. How important is this? Comfort is one reason. If you only bowl a game or two you would probably not notice too much strain on your hand. However, if you are league bowling one, two, or three times a week or more, you are going to want a grip that will not blister or hurt your hand. Just as a runner would not fare too well if he/she had no support in their shoes or if the shoes were too large or small, the improper grip can cause discomfort while bowling.
Your pro shop should determine the best grip for the level of bowling you are at currently. Conventional, semi-fingertip, or fingertip grip, are the three standard grips that can be drilled. Usually a beginner bowler would be fitted with a conventional grip, where the fingers are inserted into the ball up to the second joint. The advantage of this is it will give you better control of the ball while you are learning the game. It is also good for someone who doesn't have a lot of strength in his or her hand. This helps because more of you hand is in the ball allowing you to grip the ball much easier. As you move to a grip which only allows you to insert your fingers to the first joint (fingertip), you will give up some control but then gain a more powerful release and stronger roll on the ball. This transition will not be too difficult as long as you are not getting into this grip before your game allows. Again, seek the advice of a professional. They will be glad to help you with this important area of your bowling game.
Another area that will help you with your grip is to notice how your grip feels each time you bowl. There might be days were your fingers or thumb may be smaller or bigger depending on any number of reasons. The temperature or humidity has the biggest effect. If you find the holes are too large you may add tape to the back of the holes. Various types of bowlers tape are marketed specifically for bowling. Rosin or hand conditioner may also help you get the proper feel. You may need to do a little experimenting in order to find what works best for you. If you find that your thumb or finger holes are a little too small you can remove a few pieces of tape. Some baby powder on the back of your thumb may also be helpful to release the ball smoothly on certain occasions when you are sticking in the thumbhole. If all the tape is removed and it is, still too tight you might consider having them worked out just a little larger to allow for those days where you just can't release the ball cleanly.