Sitting in front of a cutout/mockup/cockpit poster (typically about £15 from a pilot shop) with a checklist, repeatedly practicing checks until particularly the airborne / emergency checks are second nature, can save a great deal of time, and thus money in the air.
You can always turn up on rainy days when your lesson is cancelled and sit in the cockpit for real without being charged a penny for it.
Edit: Just don't drain the battery too much, fiddling with that Garmin 430.