While Montague's dissertation rates a true "Excellent" overall, and all others offer very good information I would like to offer a few more hints.

When I start a new student, while checking the airplane over, I hit on some safety stuff, and a bit of what makes the machine fly especially the operation of the controls. Then after the first flight, and he/she has seen the model actually fly, we have at least a 2 hour ground school. We cover AMA Safety Code, Club Field Rules, and Pitch, Power, and Bank.

The use of some jokingly presented experiences can help keep the student's attention, plus a few questions of what to do in situations. You will be able to devise what you need when you need it.

Once we start actual flight training, at first I do not let any bad situations develop. I keep my throttle at 100%, always ready to recover. Especially so with the transmitters that have that da_ned "button" rather than a switch.
I also brief my student's that when I say "Right" or "Left" it is the student's right or left since if he needs the coaching, then he is already confused and he should not have to determine the model's left or right, That skill will come as the training progresses.
Take-offs start after the student demonstrates the ability to make a low approach, initiate a go-around, and NOT allow the model to make the usual left turn. Rudder control at low speeds is emphasized
Landing approaches start after the student can perform slow flight, stall, recovery, and a straight out departure at the normal cruise altitude.
The use of throttle for altitude control, along with attitude (elevator) for airspeed control is strongly implanted during the landing phases from downwind to touchdown.
All landing approaches start from a downwind point opposite the pilot to include a base leg and a final approach.
When the student can take-off straight out at an angle not degrading the airspeed, perform good turns, remain away from all pit/parking/overhead/behind flight-line, etc. areas, recover from sudden given unusual attitudes, perform an inside loop and safely recover, perform an axial roll and safely recover, then perform 3 landings without killing the engine, I say "Safe for Solo".
BTW I require a minimum of 12 flights before I clear him to fly on the club's flightline, where I may also be. So if he accomplishes the above in 3 flights, he doesn't get turned loose on the club until 9 more flights are done.

As others have commented on, attention span can be a limiting factor. A flight of more than 15 min. is a waste. More than 4 flights in a day is a waste. More than 4 or less than 2 sessions a week are generally non-productive.