The trick is to match your child's strengths with the same kind of group activities that nurture his interests. If your child's strength is singing, you might look for a choir for him to join. If soccer is her passion, find her a soccer team to join. You'll be enhancing not only your child's natural talents but also his social skills. Provide interactive toys.
Some toys lend themselves to interactive play and be great icebreakers to start kids talking.
The UCLA Social Skills Training Program notes that the best interactive toys are ones that require at least two people to use, have simple rules, are inexpensive, don't encourage aggression, and are fun by kids' standards. Board games, marbles, ball games, pretend figures, and dolls are appropriate. Teach conversation openers. Keep in mind that kids rarely start conversations with other children by shaking hands and issuing formal introductions. You need to write down ideas for conversation starters and take turns rehearsing them together until your child feels comfortable trying them on his own.