When I was in California I noticed that Benja Fallenstein seemed to have a much better thought out way of using TagTime than I did. I asked him for more details by email, and he gave me permission to share the below with all of you:

Most importantly, I make sure that all my tags fit on a single screen on my phone; and that most of my pings need to get only two of these tags: (a) a category, and (b) a Liekert scale rating from 1 to 7. (1 = very bad; 2 = bad; 3 = neutral to bad; 4 = neutral; 5 = neutral to good; 6 = good; 7 = very good)

I have TagTime linked to Beeminder, which lets me see the trends at a glance. I don't currently have any of them linked to goals which are difficult to meet.

Some goals linked to TagTime are: working hours; object-level working hours; sleep; missed pings; procrastination; "bad" (1-2), "neutral" (3-5), "good" (6-7).

I have it set to ping every 30 minutes on average and this works for me.

My categories are, tagtime tag first, meaning in parentheses:

anki (Miri: Anki) l (Leisure) m (Miri: Other) m:adm (Miri: Admin) m:fai (Miri: FAI research) m:mth (Miri: Other math) m:o (Miri: Outreach) m:str (Miri: Strategic research) mis (Missed ping, can be used together with most likely category, or by itself if I don't have a good guess) mp (MSc / PhD) p (Personal: Other) p:adm (Personal: Admin) pcr (Procrastination) s (Semimiri: Other) s:ag (Semimiri: Agentiness) s:gtd (Semimiri: GTD, i.e. Getting Things Done system) s:res (Semimiri: Other research) s:tm (Semimiri: Time management) slp (Sleep)

Additional tag:

sdy (Study -- used together with a category tag)

I have Anki cards for training the meaning of these tags.

I'm considering subdividing leisure into l:fic (fiction), l:soc (social), l:par (Skyping with parents), and l (other).