1. Although many non-aerobatic are rated for spinning, I prefer to spin only in aerobatic aircraft.
2. Don't skimp on the altitude - as high as practical is always comforting.
3. It is not a manoeuvre to be taught for one lesson only - any student undergoing training needs to be comfortable and competent in all phases of the spin. Keep doing it until you (the instructor) are completely happy with Blogg's skill.
4. Having instructed in a quasi-military environment (BAe, Aus) I prefer the Military Attitude to spinning - Pick reference points, set a well defined standard (e.g. recover after 'x' turns on a particular reference point), pre and post spin checks and etc.
Fark!