CLOWN AROUND Turn whines into giggles by whistling, popping your finger out of your mouth, or hitting yourself on the head with something soft, says Linda Valentine, who started entertaining babies on the set of a diaper commercial. Use funny voices, lead a sing-along with a familiar tune, play I Spy, and keep a toy that squeaks or makes music -- or a bottle of bubbles -- on hand.
ENFORCE CROWD CONTROL Too much stimulation from a lot of well-meaning people can backfire. "It can be overwhelming for a child when everyone is in on the act with a balloon or a toy," says Mary Brown, who specializes in magazine photo shoots. Same for toys: Don't whip out a bunch of playthings at once or in quick succession; bring out one at a time.
MAKE A GETAWAY Try taking an upset toddler into a different setting. A breath of fresh air can really soothe a fussy kid, says Sara Herbert, who's been wrangling for 12 years: "I was working on a cookie commercial once when the stars, a pair of 2-year-old twins, were having a tough time. I took them outside for a bit, and they settled right down."
KEEP 'EM CALM Don't build up your child's anticipation or anxiety before a big event -- even if you're feeling nervous. Gay Merwin, who worked on the Broadway production of The King and I, had to keep her charges -- some as young as 3 1/2 -- calm between scenes. That often meant asking eager stagehands not to play with the kids: "Otherwise they'd be wild and squirmy," Merwin says. But if your child's been cooped up all day, give him a chance to work off any extra energy before you dress him up for a big evening out.
Finally, make sure your toddler's well rested and wearing comfortable clothes. But don't expect him to behave perfectly; you should be prepared to go with the flow if he acts up or gets cranky. "Sometimes," admits Herbert, "nothing works."