I was also busy typing a response when I realised that it didn't contribute anything more than what Bjornall and other had said already.
The way I see it, there are two schools of thought:
- Come up with an acronym as long as you can manage, which includes every conceivable check that you might want to carry out in-flight, and do that just before landing. This ensures that you've done each and every check at least once during the flight. (Oh well, I'm overreacting but checking for example the hatches, for the first time since taking off, on downwind, sounds a bit unnecessary. If there's something wrong with the hatches you should have noted that earlier, shouldn't you?)
- Keep the downwind checks as short as possible, so maximum time is spent looking outside.
For me personally, I'm from the second school. My checklist works out as follows:
- FREDA check well before entering the circuit. This takes care of fuel management, instruments, radio settings etc.
- Dab the brakes two or three times to check pressure, and on most aircraft you can feel if the parking brake is engaged - the dabs will feel different with less "give". (The second and third dab are there to detect an engaged parking brake if the parking brake is a one-way valve type. You feel the buildup of pressure on the second or third dab.)
- Fuel pump on before entering the circuit, or anytime I'm operating below 1000' AGL
- Carb heat anytime RPM is below 2000.
- Mixture rich anytime before I make a power change.
- Lights anytime viz is poor, or when a lot of traffic is around. In good conditions, the aircraft seems to land perfectly fine without the landing lights on. But in bad conditions, the lights are on well before I enter downwind.
- Flaps is something I consider a flight control just like pitch, roll, yaw and throttle. I don't "check" flaps but "operate" them. Hence they're no "check" item.
Also interesting to read the POH. Or even better: have a look 'round the panel. A Warrior, for instance, requires a placard with the landing checklist to be in full view of the pilot:
Fuel on proper tank
Mixture rich
Electric fuel pump on
Seat backs erect
Flaps - set (white arc)
Fasten belts/harness
Air conditioner off
Sooo... Different ways of doing things. As long as you're a student, do as your instructor tells you. Later on, find a way that works for you, is safe and works across the range of aircraft you are flying. Anything from one or two memory items, to BUMPFITCCHC-like acronyms, to "Red, Blues, Greens, and we're cleared to land" to taking out a paper checklist, to using whatever is placarded in the cockpit.