Some of these replies make this sound so easy.... If it were, this place would be a treasure trove of beautiful bonsai. It isn't.
My advice from someone who grows trees from even seed being able to control my every move is, It ain't that easy. Many of these replies are telling you to grow it until it reaches the size you want then chop it or cut it back. Well everything also grows inordinately large also. Branches too big, internodes too long, leaves too large, roots too large.
Building a tree is exactly that, BUILDING a tree. It starts with good nebari and good trunks and great branches. All of that in scale and proportion. How you wire from the beginning and how you wire at the end may be different. Your skills will get better and what you thought was good 5 years ago may be raffle material today.
Here are two pictures of small pines by two different growers. You tell be which pine you would like to start with. Each are about 6 years old. It is easy to see that these two different growers are at different levels of technique and expertise than the other. On is developing movement and branches low early while the other does not understand the importance of this with growing a plant early. Like I said if this was easy, they would both have the same material. It's not easy.
