Never walk away from a routine that is not functionally complete but that will still compile. You might forget, or be out sick, and the module may never be finished. A simple way to avoid this is to deliberately insert a syntax error at any point needing work and save immediately. For example:
Private Function Test() as boolean
'left off here, syntax error will cause full compile to fail on next
You can use ctrl-F5 (full compile) to bring you back to the spot where you left off. Of course, you can do this as many places as you want if you are working on several locations simultaneously. This is an extremely effective habit.