well i keep it all very simple:
1: intro, interlude, or some other track i never want to hear. not a rating of quality. these get skipped over during shuffle play using foo_skip.
2: i hate the track. very few 2's in my library, but there are a few.
3: meh. i'll listen to it when playing the whole album, but don't want to hear it in shuffle.
4: i dig it.
5: yes! definitely a favorite.
i also have a heart symbol in my playlists for my absolute top tracks.
as far as where songs belong in relation to one another - i rate songs in terms of the genre/style i feel it belongs to. trying to decide if this space ambient track is better than that post punk track is just impossible, so i rate it in terms of similar music that pops into my head. because of this, i tend to shuffle either individual artists or specific genre/style categories when i'm rating tracks.
i have global hotkeys set up for all this, so i just rate as i listen. it's a slow process, but i'll get there eventually. it's really nice being able to make a playlist of 4/5 rated tracks and only hear songs i know and love
