Sean, I definately agree about table image and note-taking. I was playing last month and saw a table-coach pull out his notebook during the game and force us to admire this fact. Although he was terrible and I later adjusted to this, my initial impression was that I should avoid him.

OP, as for taking notes on yourself and the general game conditions, I keep a section open in my notes about if I was on tilt, tired, hungry, caffeinated, rushing, cold-streak'd, talkative, quiet, too-tight, etc. Was the game tight, loose, exceptionally tough, slow-moving, poorly dealt, hot, cold, drunk, etc.

The kind of notes you keep on live play will generally be more subjective than online notes. This is because people can see you take notes and you don't really want this. Therefore, you are forced to rely on your memory. I believe there is much more information at a live table than online, but it is also much more difficult to tally this information. You must do it informally most of the time.