I think that some very important information needs to be mentioned here. The following is meant only to save you possible years of time and frustration. I am not sure it is worth putting years of effort into these trees, at least not really from the ones you posted. Training starts from the roots up, so we should start from there. If you put these in grow boxes for three years. After this time, you can put them in bonsai pots. However, they might not be able to go into a proportionate size pot right on the first repotting. So then it will be a few more years. Sometiems the stumps underneath may not allow you to ever really get them in proportionate size pots.
As far as the trees. Generally, good bonsai candidates are single trunk trees. Unless you are going for twin/triple trunk. However, there are certain criteria for them. The trees you have showed have multiple trunks of the same size. Which means that it will take much pruning to pull an image out of the material. Junipers sometimes do not like heavy pruning, you might have to do it in stages. Also, there doesn't seem to be any interior growth or growth close to the trunk. Basically, you will have to do some extreme wiring, grafting, wait for back budding or all three. Also, training boxes and pots cost money, soil costs money, all the wire it is going to take with these costs money.
I am, in no way, trying to discourage you from this project. Also, I have not seen the other trees. I just want you to be aware that it is going to be several years, take money and time for material that might not turn out to be good bonsai. Also, the longer we are in the art, the better we become. In 4-5 years, you might look at these and think, what am I doing here. I know, I spent many years training material that lead to nowhere. Now, I try to get the most out of my time and money with bonsai.
I hope is helpful.
Rob
