Bonsai is an art requiring patience, especially when pruning, which is a skill acquired with practice over time.
The intent of pruning is to capture and accentuate the beauty of the trunk and spread of the branches. Using a pair of sharp scissors or pruning shears, remove defective branches and dead twigs to create what looks like a miniature, ancient tree. Carefully snip off leaves that seem oversized or out of place; aim for a triangular shape, with the lower branches wider than the upper; and create an aged look by carefully removing small sections of bark with a sharp knife to make the plant look as if it has been ravaged by years of wind and rainstorms.
Branches should be asymmetrical, so prune to eliminate those that are exactly opposite each other as well as excess foliage that obscures the trunk. To avoid pruning mistakes, place a sheet of paper in front of a branch before removing it to see what the tree would look like minus the branch.