Birthday party memories last a lifetime. A birthday bash can be a blast for the kids, yet easy on you. Here are some nifty hints from experienced party parents.

GUESTS- Try to invite children who are all about the same age. That way, they'll have the same interests, skills and attention spans.

- The old advice to limit the number of guests to your child's age still holds. Younger kids simply can't handle as much excitement as older kids can.

INVITATIONS

- Be sure to include date, time, place, who the party is for, your phone number and RSVP, if you want one. Also mention what to wear or bring to the party.

- It's a good idea to note on the invitation that you'll bring kids home. This way, you can end the party promptly, instead of waiting for tardy parents to pick up their children.

- A one-hour party is long enough for preschoolers; two hours is a good guide for older kids.

PLANNING ACTIVITIES

- Age and maturity of the kids determines the kind of activities that are appropriate. For 2- and 3-year olds, avoid competitive activities or those that cause excitement, such as races. If you give prizes, make sure every child gets one, ideally the same item. By age 5 or 6, children should be able to participate in competitive games in which only some children receive prizes, but it still might be a good idea to have prizes for everyone.

- Make plans for several more games and other activities than you think the kids will have time to do. They will go through things faster than you think possible.

- Have at least one other adult help you with the party.

FUN THINGS TO DO

- Musical Rugs: The same game as musical chairs, but played with rugs. Carpet samples are ideal.

- T-shirt Art: Give the kids white T-shirts and heat-set fabric crayons and turn them loose as fashion designers. While they're enjoying treats, set the designs by running a hot iron over each. The shirt doubles as a party favor.

- Breakfast Party: Have the kids come in their pj's for a morning party. Stage a mattress jump or pillow fight. Show cartoons.

- Backward Party: Print the invitations backward. Ask the guests to wear their clothes backward. Run the party in reverse: Eat first and end with games. Run a slapstick comedy film backward.

- Balloon Ascension: Have each child tape a stamped, self-addressed postcard to a helium-filled balloon, asking the finder to fill in where and when they found the balloon. Then head outdoors and watch the balloons sail away.

Tip: To rent a helium tank for blowing up balloons, look in the Yellow Pages of your local phone directory. The cost can run from about $15 to $35. Most places require a deposit of $50 to $100.