One of my favorite techniques to obtain larger material is to fuse young rooted cutting together. I use cuttings all taken from the same mother plant so that the bark, leaves and general character of the fused plant will be completely the same. In this way I can develop larager plants since my growing space is limited to one indoor growing room and I do not have space for really large pots or the ability to grow plants in the ground. Growing in the ground or in large growing containers would be faster and easier ways to get larger material.
Some images of fusing materials follows. Most are just early on and not totally fused. It takes anywhere from 1-7 years to achieve good fusions depending upon the age of the material, growth and the genetics of the plant.