Thanks to Omar I was listening to the podcast here with David Shaner Sensei - Chief Instructor of the Eastern Ki Federation.
http://usaikido.com/
I thought that Koichi Tohei Sensei's Four Basic Ki Principles were quite interesting:
Koichi Tohei Sensei's Four Basic Ki Principles
1. Keep One Point
2. Relax Completely
3. Keep Weight Underside
4. Extend Ki
Further explanation:
http://houstonkiaikido.org/What_Ki_4prin.htm
I think they're like the Tai Chi classics or similar, in that they only mean anything if you already know what they mean. Get what I mean? But anyway - a lot of the Chinese arts seem to come with huge lists of principles or posture requirements - 16 that, 24 this, 13 whatevers... all too much to remember. I find this approach of keeping it simple and just 4 things quite attractive.
All those 4 can equally be applied to Tai Chi, for example, 'extend ki' being like the Peng feeling. 'Keep weight underside' being about sinking the weight, 'keep one point' about moving from the dan tien, 'Relax completely' being Sung.
Is that too simple? What do you think?