Pruning is important to keep your shrubs healthy and looking nice. Some pruning is best done by hand by snapping off and removing the length of the growth for the season by shutting down the growth of a branch.   This will cause the tree to bud back and will fill in the tree with more branches. This will not work on all trees or shrubs.

Some times you will need to use tools for your pruning depending on the plant. Using an electric pruner is not a great way to go because it hacks up the shrubs and is not natural. By pruning by hand you can select just a few of the leaders and tops of the plant you can get the shrub back to a nice trimmed size with a natural healthy appearance that is also better for the plant. 

The best time to prune for almost all plants is right after they are done flowering. This way you will not be pruning off next years flower buds.