Trust some one to lower the tone of a good and serious thread "stick to your guns" to coin a phrase I am sure you are all aware of the term and it's common usage as was not meant to be a pun
I would like to agree with every thing tiny and liz have said and also it might be worth your while listening in to the captins meeting to see what they are expecting too. I would also sugest you read up on the rules and be aware of any hand signals the marshals use.
As much as possible don't be "seen" to focus on a player as you will give his or her position away. Not so important once it's obvious every onre knows were all the players are. Like liz said get in there when you need to.
Enjoy ,I know I did at the self marshal event at nottingham