I air-layer pretty good
I took two 2-2.5" layers from the top of a mature (10"- 14" at base now) tree I started from a cutting 27 years ago. The cutting came from a bonsai I grew from a 2yo seedling. That tree is in a 27"x17" pot and it is 6" or 7" at the base. I have the top out of that tree...
