Sounds like you need to carry tools and do the grunt work for a yamadori collector.....
. I do not understand the weather in California at all; or the conifers you'd likely be collecting. I have collected Juniperus virginiana many times successfully from railroad tracks and placed in a mist house used for rooting cuttings. Metal frame, double layer inflated poly. The house had 60% shade cloth, automated exhaust and intake for temperature control, and a mist system (4 differerent ones actually). I placed my trees next to a mist zone and left them there for two weeks. Then moved them to an open-ended 40% shade hoop house for a few more weeks before placing in full sun.
I've heard you should put the trees in full sun right away and also heard to put them in deep shade...... Those two individuals never had a high success rare for J. virginiana. It seems to me that different species require different aftercare, media, etc.
I used to bring a rare plant or 6-pack of high-end beer to nursery people that I wanted to learn something from back in the day. Jack Daniels works in Japan. Anything you get from an Internet forum will likely be incomplete including from me as there are lots of little details.