Well amigo you came to the right bowling site because
I wrote the book on
HOW TO BOWL MORE STRIKES!
The problem with most bowlers who wanna bowl more strikes is that they get intense and aggressive about it both mentally and physically and so if and when they don't get a strike, they get very frustrated and instead of being happy that they got whatever pinfall they achieved, they focus on what they did not get. And as a result, negative thinking and tension enters the mind and body which results in more missed shots.
One of the keys to bowling strikes is to 100% focus on what you want. Visualize it mentally rehearse the shot, feel happy and relaxed about it ( you may even feel as if you are making this up) and then JUST DO IT!
Go ahead and do this the next time you bowl and notice the difference.