>>606379
The two short answers are 1. experiment and 2. flickr
1. While some things are designed with certain configurations in mind, most kusudama (and especially sonobes) can fit together in a variety of different unit configurations. So the easiest thing before you invest in a project is to consider how many units make up one face or vertex and see how they look together.
2. Flickr has a great origami community and is a good starting point to look for inspiration and often times artist will have instructions or cps for their models. Also with practice you can figure out how to reverse engineer models from pictures and notes about the model.
picrel: https://flic.kr/p/2mbMt8f 90 unit sonobe dodecahedron. most any sonobe will do.