Stay calm.
When I teach aeros the first thing taught is unusual attitude recovery - developing from basic stalls to inverted / nose high / nose low / rotating / stalled & rotating etc.
Part of this is includes the student being taught to centralise & brace the controls if control is lost until the flight condition is recognised.
If it goes awry it will be either some form of dive, or some form of spin ie upright or inverted.
As long as there is time try to get the student to recognise the situation.
They should then be able to recover.
Otherwise tell the student the flight condition & command them to recover, or
Take over & tell them what the situation is while recovering. (if the situation warrants it)
Have fun!
[This message has been edited by Tinstaafl (edited 13 September 2000).]