2) be observant, especially for things that weren't on your agenda for today's shoot
3) don't blow a great shot with technical issues - that's just mickey mouse - get that crap out of the way through lots of practice and careful routines, even check lists and being careful - and if hand holding under borderline conditions, take several shots so at least one will be sharp.
4) give yourself several possible shots to choose from whenever possible - often I find that the penultimate shot that I so carefully positioned and framed is subsequently beaten by an even better shot as I literally and figuratively circle round to where I started, doing a better job on the second go round
5) really work the scene - don't leave until you are sure you have done the best you can
6) arrange as much as possible before the decisive moment so that when it comes you are ready
7) put the extra effort in so you arrive before sunrise, go out in bad weather, etc.
8) have an aesthetic check list too - background ok, light perfect, edges strongly composed, subject best framed, etc.
9) keep your equipment relatively simple so you aren't changing lenses when the perfect situation comes up
10) stop believing in luck - it's all sweat equity, with a few smarts sprinkled in