New to bonsai, looking for advice about starter bougainvilleas

[kingtopher]

I have been interested in bonsai for a while, and have played with some jades a little, but I just decided to take the plunge and bought a couple of bougainvilleas to mess around with and learn on. I’m in San Diego and grow some in pots already and they’re almost impossible to kill and grow like crazy even with neglect, so they seemed like a good choice. If I had to guess I’d say they’re both maybe 3 gallon pots.

I’m attaching some photos and would love any advice about chopping them back for the first time. I marked my rough plan with red but would welcome any advice. I’ll make a reply with the second plant in it. Thanks so much!

 

[kingtopher]

Here’s the second one and what I think seems like a good front. This one isn’t as obvious about what I should do.