As a newly qualified PPL with less than 100 hours I am more than happy to use the checklist on the ground before and after my flight. Even with the checklist in hand I have forgotten to set one stage of flaps on take off in the Robin. Only noticed when I went retract them at 300ft! In the air I use mnemonics. I have enough on my plate aviating (isn't that the first rule?) to keep me occupied.