Iuse a note book to log general info such as fuel used, hours on engine, and anything I needed to adjust at the field. My memory is not as good as it used to be so I find myself forgetting many things if I don't write them down.
One thing I always do is use a check off sheet before the first flight of every session. I fly bips and need to use this list so as not to forget anything that may be critical when I assemble the plane at the field.
Also a list of things I need to bring to the field........... like wings, gas, small tools, radio............. laugh if you must but every week someone forgets to bring something that they later need at the field. I can't count the times guys have forgot their fuel or smoke oil or even the darn radio.
I now bring extra gas and smoke oil as can make enough profit on selling to the "forgetters" to help pay for my personal fuel use. I used to just give it to the guys, but it seemed that a couple of guys were starting to come to the field with empty tanks all the time.