Re: Correct Movement in Aikido
I don't think that tiring your body before practice makes you any more receptive to anything but building stamina and focus. It would seem to me that being tired adds another distraction to building the awareness of what we are learning. Repetition builds muscle memory and guided trial and error provides for learning aiki.
Having a background in instructional design, I might suggest analyzing the techniques. Look for the essential principles and motion elements. Attempt to prevent bad habits before they start. Maybe the principles and motions can be taught independently so that the forms become less complicated for the learner. I understand some martial arts have square forms that round and flow as the student progresses.
This view is given to the more experienced to contemplate.