The bonsai pruning is done to shape it, ie, with the modeled some aspects of bonsai pruning. Therefore it is important to know how to properly prune a bonsai.
We will use pruning to remove faulty branches (whose growth is not aesthetically normal) or unnecessary (those that do not want to leave).
Generally the best time for pruning is when winter is ending, at that time the bonsai is idle and no injuries expel as much sap past.
In general, for s primary branches and recommended a concave cut because it is better and faster healing. Straight cuts or leaving a stump besides being anti-aesthetic take longer to heal, so you can put in health risk bonsai.
In the case of secondary branches, as well as the primary branches, is a preferable concave cut.
If we want to shorten the branches of bonsai to suit or get the way you want you should make the cut diagonally upward as shown. The straight or perpendicular cuts take long to heal, and diagonally down should never be performing.
It is important to understand these concepts when pruning a bonsai because if done improperly we can not only disfigure our bonsai but also endanger their health.