Prepare ahead of time. Avoid fights and meltdowns by scheduling playdates at times when toddlers are likely to be in a good mood, such as in the morning or the late afternoon (post-nap, of course). If the playdate will be at your house, be sure to double-check your childproofing beforehand -- your little guest may get into something your child knows is off-limits.
Keep it small. Try to limit get-togethers to one friend at a time, especially if the kids are playing indoors. Your toddler will have a much easier time learning to socialize with just one other child; plus, fewer kids means there's less chance a fight will break out. It's a rule Farrah Griffin, mom of 2-1/2-year-old Kennedy, swears she won't break again. "When I set up a group playdate with Kennedy and her friend and my older son and his friends, there were tons of tears and battles," says the mom from Renton, Washington. "It's definitely easier for toddlers to interact one on one."
Go over the house rules. Tell the kids what they can and can't do, but keep the list short and simple ("We always eat in the kitchen, and we don't play in Mommy and Daddy's bedroom"). The longer you lecture, the more they'll forget.
Let the kids choose the agenda. Plan a few activities you think they'll like, but let them decide what they want to do. (Just make sure you come up with plenty of ideas, since toddlers have a notoriously short attention span.) If they simply play alongside each other at first, don't be concerned. They're still learning social skills by watching and mimicking each other, so there's no need to force them to interact.
Turn off the TV and computer. Toddlers won't learn social skills staring at a screen. The exception: Watching a DVD or playing a computer game can help the kids wind down when their perfect playdate comes to an end.