I don't have a checklist in front of me, but I believe the initial check is every flight and the full check is first flight of the day.
I completely agree with the comments about scheduling the checks. We've seen a reduction in certain parts of maintenance by reducing the scope of pre-flight checks. If you open one panel four times between each flight, not much will change, but the closures will certainly show more wear.
I wouldn't be surprised to see similar results with some of the cockpit checks that are done.