Ellis Amdur
Amdur Sensei trainins in the Koryu arts and has written some excellent books about aikido, in particular 'Hidden in Plain Sight' where he explores he origins of O'Sensei's power (Internal Strength?).
He wrote the following article for the aikido journal - its some pretty nice advice. Here is the full article
So are his suggestions for training.
1. When a senior trains with a junior, he or she should ONLY ONCE completely stop the technique in a round of practice of the technique. .....
2. Any move or response that ignores basic combat criteria (for example, if I ground myself while leaving my eyes in easy reach of a thumb-gouge) is wasting time - if you care about the martial side of things. ....
3. NEVER stop the instructor’s technique in front of the students. ...
4. Don’t make the dojo a “Darwinian” venue, unless you are working out of a garage or barn that you own. If you break new members’ confidence, merely displaying that you are too strong for them to touch, and they too stupid and inept to do any better, they will discontinue.
5. “Simply grounding out” in the middle of the technique, making it impossible for the junior to bring off any technique, is an “old school” aikido cliché, similar to demonstrators making it difficult for cops to carry them away from the gates of the Pentagon. Make it challenging, but not impossible ....
6. Unless you are clearly and openly practicing a “principle,” in which you may start with expansive “over-movement,” don’t exaggerate movements in a way that violates basic principals.