Another good crit trick is to think about the circuit. Let's say you have one long strait, then a backside section with lots of corners, then a good training might be a 1 minute L4 effort, followed by 4 10s sprints, with 10s recovery after each.
When you ride crits, think about where you are struggling, what is happening in the race when you are hurting, and address your weaknesses. This applies as much to bike handling and positioning as much as fitness.
Usually I ended up right at the back of the peloton getting totally fcuked up by the accordion effect in the corners, and spending 30 minutes yoyoing on and off the back before getting dropped. But one day there was a very small peloton of just 19 starters and I was able to get near the front and it was a completely different experience. It was almost easy, I swear.
I sucked at crits. Holland is very strong on crit racing and I can remember thinking I was going to die hanging on the back of a 30 man single file peloton through the cobbled streets of Enkhuizen with new Milram pro Wim Stroetinga on the front.
I was delighted to see that Stroetinga was 2nd in the Cancer Crit in Australia the other day just behind McEwen ;-)