How to bowl the correct way is most important. You must take in consideration a few basic techniques that are essential to improving your score.
Note: If you are left handed these are reversed.
1) Your Approach to the foul line:
This should feel comfortable and natural. I use a four step approach and lead with my right foot. Start by straddling the middle dot on the approach and walk, leading with the right foot, to the foul line. Adjust where on the center dot you stand by how close to the foul line you finish.
2) Your Timing:
Your push away is where it all begins. Timing is adjusted by either raising or lowering your ball in your starting stance. If you are getting to the line before the ball then raise the ball a few inches and visa versa if the ball is getting there before you do. A little trial and error will fix this problem.
3) Your Arm swing:
You want to develop a nice fluent arm swing. Think of it as a pendulum on a clock. Push the ball away and extend your arm during your first step while holding the ball a little to the right to allow for your hips. Allow the ball to fall in your swing while gripping it slightly. Do not force it with your arm, let it fall to create a nice pendulum swing. Bend your knees slightly to get closer to the floor. Practice this and you will become smooth and able to hit your spot on the lane easier and more often.
4) The Final Release:
Try to keep your hand in back of the ball when you start and finish your approach, preferably with a finger tip grip. This allows the ball to head toward the spot on the lane that you are looking at and hit it more often. Try to keep your wrist straight or slightly cupped for more turn on the ball. When the ball comes past your ankle on your sliding foot, pretend that you are squeezing the ball. This will give it a nice turn and cause pin action.