sauce

Do some searching and look at other BC bonsai to get an idea of what you want your tree to be. The flat top style which Ralph spoke of is an old mature tree and there are usually no lower branches, all of the branching and foliage is at the top of the tree. Low branches indicate a young or juvenile tree. Then again BC develop very nice tapered and fluted bases when aged in the ground or a grow box as Bob and Aaron said. It is a matter of what you want your tree to look like. Look at some pictures of other BCs and decide where you want to go with it. You can keep it in the pot and develop the top or plant it out and develop the trunk.