Logging
Well since I wasn't entirely sure on mine I took lots of photos (on the ground and when safe in the air) to remember it by, and as well as keeping any invoices for landing fees I got my log book signed at the back.
I did this too for my CPL. Actually twice as I did 2 large routes to be sure and to enjoy myself in between CPL and MEP/IR. Flying into Duxford first time was pretty good.