The following styles are the most common bonsai patterns used today that reflects the culture and personality of its owner. Click style name for image of the bonsai style.

Formal Upright
One of the most natural styles where the trunk is perfectly straight. The branches should alternate left to right to suggest age. The bottom third branches are removed and the remainder are drawn downward.

Informal Upright
This style is characterized by a lightly curving trunk displaying the harsh elements of nature. This can be achieved with ease using wire and/or cords. It is as appropriate for conifers as with deciduous trees

Broom
A straight trunk that begins to divide and subdivide into many branches. The characteristics is its thick and finely branched crown. Some trees for this style are Beech, Elm, False cypress and Maple.

Slanting
So called because the general slope of the trunk is highly pronounced. The branched should lie horizontal or droop slightly downward. The surface roots has a unstable appearance but have a well anchored impression.

Windblown
Rare in nature; This kind of tree is found on cliffs or mountains. The trunk, branches and twigs are trained in a single direction to give the affect of a strong wind and storm.

Clasped to Stone
is a much loved but difficult to create style. The size and shape of the rock should complement the plant that is set on a gravel or water dish. A whole chapter could be spend on this style.

Double-Trunk
Formed when a single tree divides into 2 trunks right above the ground. The two trunks must never be exactly the same height, one considerably shorter. The overall shape should be conical and the branches not crossing between the two trunks.

Clump
Looks like a group of trees, but like the double-trunk style grows from a single root system. The overall shape should be conical with the larger trunk in the middle and working outward to smaller trunks.

Raft
A line of separate trunks all growing from a buried and rooted branch. Very rare.

Forest
A number of trees of different heights and thickness positioned into a harmonious group. For aesthetic reasons, the rule is for an uneven number of trees.

Cascade
A thick trunk that curves downward as close as possible to the point where it raises from the pot. There should also be a short conical head with branches alternating from side to side.

These are just some of the bonsai styles. There are many other styles that can be created. I suggest purchasing a good Bonsai book to learn more about creating the different styles.