Back when I owned a field, there were a couple of times where when I'd see one of the loudmouth/braggart types moving up (woodsball) I'd very intently watch an empty section of bushes.
If the guy was paying any attention (they don't always) he'd see that and think I was watching where a player or group was, anticipating contact where he was heading.
And so he'd instead "flank"... right into the spot where the players actually were, and get ambushed.
Didn't always work, because even the experienced players will often "tune out" the referees. Although one time I managed the same thing by performing a paintcheck on an empty bunker. Braggy goes deep left to flank the bunker, keeping a close eye on it... and walks right into a clean shot by another hidden guy.