my tip: find your strength(s) & use it to your advantage.
case in point: this is my first year crossin' & i've spent most of the season training for a marathon. i am also just a better runner than a cyclist. i hold on as much as i can & when the barriers &/or a run-up comes along, i pass more people or gain more ground than at any other point.
(this is not to add to a to-run-up-or-not-to-run-up discussion, just to point out that you should find what you're good at & use it to your advantage.) i know so many people that aren't sure what they are good at (in various sports) & they're constantly lost as to what they should do & when.
also: don't give up at the beginning. a friend of mine was in the lead of a race but held up to get some help from others to pull. from what i've seen, that tactic really doesn't work in cross. put the hurt on 'em early or end up like someone i know (brett).
i hope that helps somebody pass that one person they're gunnin' for.