I think it is very much like the typical productivity tips - prioritize and focus on the tasks needed for the project.
My own rule of thumb is to also not leave messes for others - which means if I realize I can't finish a project I either need to not start, or get it to a good transfer state before I leave. Also, clean out your files, desk, computer, etc. transfer or archive needed records, destroy the rest (following your company's document retention policies).
Cleaning out my stuff was my favorite part - very cathartic. It also meant that others did not have to go through all of this stuff and figure out what it was and what to do with it. It seems trivial, but cleaning up after others is a huge PITA and time suck!
Good luck!