Every experienced bonsai enthusiast has his/her own personal idea of what bonsai is to them and what defining factors make them aesthetically appealing.
"Don't be drawn into the trap of taking everything that this person says as gospel!" This applies especially if you are using a book as a reference when you are situated in a different part of the world from where it was written. If a beginner is unable to have the experience of being taught the important principles of bonsai by an expert, he must obtain as much material on bonsai as possible - whether this may be just pictures of trees, discussions on the different styling processes involved or lists of suitable species to use. This mass of information will familiarise them to bonsai and help them gain experience by experimenting on cheap bonsai material. Frequently going to bonsai nurseries and bonsai shows will also allow the beginner to see true bonsai in real life from all sides, opposed to the usual 2D format. This will enable the beginner to see the way bonsai should be displayed and what the end result will be like The two basic styles of bonsai are the classic (koten) and the informal or 'comic' (bunjin). In the former, the trunk of the tree is wider at the base and tapers off towards the top; it is just the opposite in the 'bunjin', a style more difficult to master. Over the years, bonsai enthusiasts have frequently tried to reclassify the styles, and their many sub-divisions into which plants can be trained. Once you understand the principles behind these designs/styles, you will have a reference point from which to assess a tree's potential for bonsai and to decide what style suits it. If you study very carefully the way trees grow in nature, it is possible to design a realistic bonsai without knowing the names of these styles. You do not need to stick strictly to the precise rules of your chosen style: adapt them to suit a plant's natural habitat. When you start a bonsai, always remember that you are working with a living plant. Look carefully at its natural characteristics and you may discern within them a suitable style, or styles. All conifers are reasonably unsuitable to the 'broom' style, for example, but are very suitable for all other styles, especially formal and informal upright - to which they are particularly suited. Often you can train a plant into several styles, even if it is basically upright like a beech or elegantly slender like a maple. Even if one style only really suits a particular plant, you still can interpret this in many different ways. Shrubs like azaleas that are not tree-like in nature have fewer restrictions in the style you choose, but, generally, it is best to base any design on the way a tree grows in nature. People that are still learning the basic principles of bonsai should not try to train a bonsai into a style totally unlike a tree's natural growth pattern, although this is quite possible as you gain more experience