viewtopic.php?f=130&t=24379
I thought about this as a good starting point to consider....and often overlooked.
Do not allow more than 25mm of straight un-tapered section on any part of a tree which is 150mm in height. Preferably less in the branches
Do not allow more than 50mm of straight un-tapered section on any part of a tree which is 300mm in height. Preferably less in the branches
Do not allow more than 75mm of straight un-tapered section on any part of a tree which is 600mm or above in height.
This excludes formal upright types of course.
There is always flexibility and exceptions which should be judged on a case by case basis.
If you follow those rules, you are on the right track. If you don't.......I predict possible problems down the line.
If you don't care, disregard all this..

If you have some rules which you stick by, please include them. I want to know them too! Wiring, cultivation whatever!