last time I played a scenario, it was out of state, and I traveled alone so I made an I.D. card to carry with me on the field in case anything happened had my name, an emergency contact number, so on and so forth.
And get familiar with the rules. Just knowing the ins and outs of the rules can be a game changer.
I played a scenario that had a rule structure which allowed the introduction of props as long as they were approved by an official. So a couple of us came up with "poison". We took a bottle of water, discreetly marked the label with a sharpie, introduced a paintball to a push pin and put two tiny drops in. Shook it up and got it into the general's "safe area". Had a ref witness the whole thing, so one sip and we were 500 points up, and the other team had no direction for half an hour.