How do I get more blooms on my shrubs?

In short, stop pruning the buds off.  Blooming takes time and energy for a plant.  A hormone typically needs to work it's way out to the tip of a branch, or wherever the blooming locating may be, and have enough time to develop into a flower.  Many times this is pruned off prematurely and the flower never comes.

Simultaneously, the plant is stressed from the pruning event.  It now has fewer leaves and green surfaces to capture sunlight for photosynthesis.  It's very hungry without these leaves and devotes all of its energy into reproducing them as fast as possible.  The last thing it can do is muster up enough energy for flowers.

The best thing you can do to promote blooms is to choose the right plant for the right place.  Know how large the plant gets and allow room for it.  Allow it to grow to its natural size so that it can branch out and develop the blooms you want.  Prune when necessary, at the correct time of year, and using correct techniques.  Do not hedge trim your shrubs!  This not only stresses the plant and prevents blooms, but decreases the plant's life span in general and creates a host of other vulnerabilities.