The first step is to become familiar with your bonsai. Observe its branches and decide which side should be the front. Generally, the back tends to have more fullness and lower branches and the front tends to be more open allowing the trunk to be viewed.
Remove all dead/unhealthy growth and anything else that is obviously undesirable. Remove all leaves growing directly from the trunk and main branches. Also remove any tiny, young growth/branches growing from the trunk especially those towards the bottom.
By clearing out the foliage along the trunk line, the branch structure should become more visible. Starting with the biggest branch low on the trunk, begin deciding which other branches should remain and which ones should be removed. Normally when two or more branches are coming out of the trunk at the same level only one is kept and the others are removed. A strong bottom branch off to the left is generally followed by a strong branch off to the right a little further up the trunk and then a rear branch to bring some depth into the tree. This basic pattern is often repeated up to the top of the tree and is a good starting point in developing branch placement.
Any secondary branches growing vertically should be removed as well as any branches growing back in towards the trunk. The objective in bonsai is to make the tree appear much older than it is. A tree in nature is usually more spread out with the majority of foliage and young growth on the outside of the canopy and not along the trunk. Also, any secondary branches growing out from the bottom of the main branches should be removed.
The overall shape of the most trees is triangular, implying that the bottom is wider than the top. Trimming all branches so that light can penetrate down to the bottom branches is very desirable. This is achieved slowly by developing ‘foliage pads’ which do not overlap one another either vertically or horizontally.
A good bonsai has a well-tapered trunk. One of the easiest ways to achieve this is to drastically cut back up to half of the top of the tree. A side branch can easily be wired into place to form a new more slender apex. Sometimes only the bottom couple of branches are kept.
After the majority of trimming is done, the tree is ready for wire. This is when the shape and character of a tree really comes alive. There are different schools of thought when it comes to wiring. If needed it’s best to wire the trunk line first. The trunk and branches can be wired so that they look a lot older. This is done by putting slight curves in them by bending them up and down and from side to side. The wire should always be put on at a 45 degree angle and should never cross another wire. It is also very important to remove the wire after 1 to 3 months before it bites into the tree.