I’ve used all kinds of systems for tracking my time, but by far the most effective is a pen and paper. At the end of the week everything gets reviewed and inputted into the digital tool du jour (I really like Harvest), but for the day-to-day mechanics of keeping track of where I spend my time nothing (so far) has been better than writing it down.
So, I made a form. I print a stack of these and keep them on a clipboard. It’s a small thing, but I thought I’d share just in case anybody else was considering going analog for their time keeping as well.
(Incidentally, it looks a lot better printed than it does in Acrobat.)