down wind One is obvious to slow up to a safe speed or add flap to reduce that speed. Watch where he turns base and delay your base turn. Widen your downwind track to extend your track distance compared to him. On final fly a curved final left and right to again extend your track distance
Slowing down downwind is seemingly an unheard of procedure for PPL's, its far to dangerous for them to fly level at approach speed downwind. Its ok between 500 feet to ground level though with idle power.
The problem with slowing down downwind is that it can obstruct the aircraft behind so its not a good procedure if you have aircraft close behind but we do teach it and expect it as an option. The best place and very obvious place to increase your circuit spacing is on the climb out path and guess what, apart from final that may well be your slowest point in the circuit and usually the only point where you are heading away from the other circuit traffic! This wont work of course you have learnt to fly by numbers because you will have to turn at 500 feet!
If however you believe in the use of good judgment and situational awareness you could extend the climb out path straight ahead to even circuit height before turning and that can increase spacing for aircraft joining cross wind or downwind or just from any other aircraft in the circuit.(its also handy for a tailwind on crosswind) Its not about pushing in, it's about letting others in too, by giving them some room!
Going around from base leg was always a military option and I belive its a useful option in a civil circuit but the military circuit and discipline is far more professional and if someone goes around from base and final at the same time it could be more interesting than I would like to think about!
You have to teach the overhead joins for the PPL because for many students that gives them the time and breathing space they need to sort out what may be a complicated six runway airfield.( 8 in the day when we used to fly to Blackpool). With the direct join you have to get it right first time on entering the ATZ, with the O/H join there is more chance of correcting mistakes early on.
I give students the option of what join they want to make and very few ever select the direct option. You have to remember that some students will have less than 10 hours P1 when making an away landing, they need the safety net of an O/H join!
Circuit collisions are caused by poor situation awareness coupled with not listening out and looking out properly. I cant think of any collisions that have happened above circuit height in an ATZ so joining o/h is just as fraught as joining direct in my opinion