A typical 3-year-old doesn't fully understand the meaning of friendship and might not have strong bonds with playmates, so you can consider constructing the guest list without soliciting his opinion if that's easier on you. But most 4-year-olds are familiar with the notion of a "friend," and they will have some opinions about the children you should invite.

An intimate gathering

A small group of children your child knows through preschool, play group, or the neighborhood tends to work best with 3- and 4-year-olds. A good rule of thumb is one guest for each year, so that means three or four guests. (Invite a couple of extras if you want, though, because at the rate preschoolers get sick, it's likely you'll have a no-show or two.)

Count on parents staying for the party since children this age typically aren't independent enough for a drop-off party.

Crowd control

Do you have a large extended family or live on a block full of kids? A big shindig might seem like more fun to you. You can successfully pull this off if you stick to the basics – gather everyone in the backyard or at the park (less mess in the house!), barbecue burgers, pass out some bubbles, and play music.

But even if you create a relaxed, low-pressure atmosphere, be prepared for your child to melt down. If this happens, don't be afraid to pull him into a quiet space for a moment where you can talk and snuggle. Some individual attention will help your child feel more comfortable in the big group.

Twice the fun

Here's another option: Rather than one big party, consider holding two smaller gatherings.

For example, you could invite your family for dinner the evening of your child's actual birthday and then host friends on the weekend. Or you could gather the neighbors at the park for cake after dinner and then pick another day to take a few preschool friends on an outing. If you go this route, make it easy on yourself and keep the two events simple – a family potluck plus a trip to the ice cream parlor with a few friends, for instance.

Also, there's nothing wrong with sticking to a family party. Three-year-olds who aren't in preschool might not have strong bonds with friends yet and may feel more at ease with their relatives. 

Crafty invites

While your child probably can't write the invitations, he can help with the process. You could scan one of his drawings and print it out to make invitations. Or you could print out simple outlines of a flower, say, or a ladybug, and ask your child to color them in. No time for handmade invites? Let him help choose cards at a shop or online. Also, there's nothing wrong with emailing an invitation.

Be sure to include a reply-by date, an end time, and any special instructions for guests (wear paint clothes, come in your pajamas, and so on). Also let parents know whether or not you'll be serving a meal for them and their kid.