Refrain from watering your jade bonsai tree for at least two to three days before pruning or pinching. This will slow the rate of new growth so you can carefully size and shape.
Snip away any branches or stems that are damaged or diseased and dispose of them. This should be done any time you notice any damage on your jade tree to avoid insect infestation or disease.
Pinch off the top 2 inches (or more, depending on your design and size requirements) of new growth to return your bonsai to your desired size or shape. Remove any leaves that sprout in areas that ruin the design of your bonsai. The tree will begin producing new, healthy growth from these areas within two weeks.
Remove any branches of your bonsai that are growing inward toward the trunk or down towards the ground. These branches sprouting in odd directions will ruin the balance and overall shape of the tree.
Prune the roots of the jade tree any time you repot it, which should generally be every two or three years to freshen the soil. Cut off the top inch to 2 inches of the longest roots to stunt the tree's production for a time, allowing you to keep it small and contained.
Water your jade tree deeply after pruning to encourage the new growth to start.