Copy code to a text file:
Ever spent more than 15 minutes looking for that 1 or 2 lines of code you saw just a few days ago but can't remember where?
Since I suffer from SomeTimers disease (some times I remember, some times I don't)
when I come across a nice little snippet of code I copy it to a text file with a brief explanation.
It builds up surprisingly quick, and is never more than a few mouse clicks away.