Last weekend was the State Championship Omnium in Wenatchee, Washington: time trial, crit, and heinous road race, and each stage contributed points towards deciding the overall winner.
(1) I need to work on my confidence around corners and descents.
(2) When you hurt, EVERYONE hurts. Just put your head down and keep going. And try not to puke/fall over/pass out.
(3) Always bring extra water. You never know when you might be 2 hours early for your TT, or have to stay an extra 2 hours after your race finishes...
(4) Always take the neutral feed. The water will be useful. You can always dump it (especially on your head, in hot weather).
(5) Always sprint. Especially when you have no idea who was ahead of you.