No doubt this will be moved to the Instructor forum shortly. In the mean time, perhaps some comments would be helpful.
The forced landing is one of the most detailed and longest briefings, which I won't attempt to reproduce here. Important points however:
Low key is simply "the end of the downwind leg". It may be 1000'agl or any other height, depending on aircraft type. It exists because it is generally easier to land from the end of the downwind leg than from anywhere else - it is the most familiar point from which to commence the approach. Thus, get the student to navigate to low key, and you maximise his/her chances of successfully landing. Not "guarantee", just "maximise"!
Flap selection: flap should not be used to "make it in". If no flap was used, your aircraft should touch down about halfway down the field. Use of flap simply slows the aircraft to minimise landing roll, and moves the aim point to the beginning of the field to maximise landing distance available. This technique avoids students depending on flap as a replacement for good judgement.
Wind: in nil wind (PA28 only), try getting your student to turn base when the aim point is about oen to two chords behind wing trailing edge. In >20kts, turn when aim point first appears behind trailing edge. >30kts? Don't teach this exercise - it requires too much judgement for the average pre-PPL student!
Whatever the wind, turn at the appropriate time in a wide racetrack pattern - don't turn straight towards the field unless the aim point is moving up in the windscreen (normal aim point adjustment taught from first circuit lesson).
Angle of bank for this racetrack turn is typically 5° to 15°. More than this will commonly result in a too-high overshoot. If the student initially turns too steeply, and is getting too close, stop the turn (or diverge from field) to lose height without getting any closer to the field. If the student is getting low, s/he can always turn directly towards the threshold.
Extend 1st notch of flap when you are
certain of landing in the field. Adjust attitude downwards to maintain airspeed, and wait for glide to re-stabilise with new aim point closer to beginning of field. Extend 2nd notch of flap when
certain of landing in the field. Adjust attitude downwards to maintain airspeed, and wait for glide to re-stabilise with new aim point closer to beginning of field. Extend 3rd notch of flap... you get the picture.
I hope this helps. Two very good books are the Trevor Thom series (Aust & NZ, maybe SA as well) and RD Campbell
Flying Training for the Private Pilot Licence (UK).
Closing note: if any student calls you a "stupid little *****" or similar words, either take him to the CFI for an Attitude Readjustment Program, or tell him to find a new instructor! Do not put up with this kind of

or you'll just end up

!
Cheers,
O8