For my daughters 4th birthday I did a carnival theme.  The director at my daughter's day care warned me that not many children usually attend parties for some reason, so I invited family and friends as well.  For invitations I wanted to use popcorn bags, but only found them in large quantities.  I went to the snack bar at a local department store and asked to purchase the popcorn bags.  The girl behind the counter at first looked at me strange, but I explained how I needed them for invitations for my daughter's birthday she happily gave them to me for FREE!! I took poster board and cut one piece to fit in the bag, slightly longer.  I used a popcorn air popper (no grease or oil!)and popped popcorn.  I glued the popcorn to the top of the pasteboard so it looked like a bag of popcorn.  When you took out the pasteboard it read, "Come to Heather's 4th birthday for a carnival of fun!". I received such compliments from my coworker and the teachers at my daughter's school. I held the party at a picnic area across the street from my house.  I had a backup plan to do the party inside for rain. For the party I decided to have several activities to keep the children busy.  First we decorated clown hats.  I made cone shape hats out of red, yellow, green, and blue poster board.  Solid colored, store bought party hats will work too.  The children decorated the hats with pom poms, glitter, markers and jewels. For food I served hamburgers and hot dogs. All of the table accessories I bought in a dollar store in the colors of red, yellow, blue, and green. After the children ate, I had several "carnival"games for them to play.  The games consisted of basketball, knocking down bottles with a ball, ring toss and toss a ball in the clowns mouth (a posterboard glued to a box in which I drew a clown and cut out the mouth).  At the first game, each child received a loot bag.  After every other game they received a prize (crayons, coloring books, favors, etc.) for their bag. Everyone was a winner. I also passed out cotton candy.  My sister dressed up like a clown and painted the children's faces and posed for pictures for the thank you notes.  I baked a two-layer cake (the person at my grocery store bakery suggested I use Whipped Icing by Betty Crocker, it just as good ad the homemade)  and purchased a carousel place between the layers.  I made clown ice cream bowls for all the children.  This consisted of a scoop of ice cream, M&M eyes and ice cream cones frosted for the hats.  Overall everyone children and adults had a lot of fun and the party cost me around $100 food included.