My son's 4th birthday party was a pirate party.  I started off by decorating the front of the house with a skeleton from Halloween that I put in my old pirate costume.  He had a sign that read "This way to buried treasure".  The front walkway was lined with pirate flags and the awning had black, white and skull & crossbone balloons hanging from it.  The front porch had fish net with various plush sea creatures captured in it.  I spread sand on the porch and put a treasure chest (made from a cardboard shoe box)filled with jewels, Chuck E. Cheese tokens for gold coins (the children took them home later and seashells to give it that beach effect. My dining room was the focal point of the decorations.  The tables were done in black and red tablecloths, skull and crossbone banners, parrots, toy pirate ship and more jewels, coins and seashells spread between the serving trays. All of the food was in shell shaped dishes and appetizers were served with sword shaped plastic toothpicks.  The food consisted of french bread pizzas with sails made of construction paper to look like ships, hot dogs wrapped in cresent rolls for the kids and a deli tray for the adults.  I made telescopes out of heavy cardboard tubing from my work, swords from cardboard and painted silver with black handles, hook hands made from black plastic cups and cardboard hooks covered in duct tape for durability. There were eye patches, temporary pirate tattoos and makeup for that pirate look. I made a treasure hunt cake that had enough of a gap between the layers to put candy necklaces, rock candy and chocolate covered coins. There were also cupcakes that were iced vanilla with blue swirls (water effect) and topped with Treasures candy. I also found root beer barrels, purchased cannons from the Gettysburg museum and placed Whoppers candy for cannonballs next to them. We had a treasure hunt with various rhyming clues like "I do the burgers, steaks and dogs, but this heat doesn't require any logs. BBQ grill)  There were children in age from one to fourteen (mostly family) so the older children helped the younger ones on the path to the buried treasure which was located in an old cedar chest placed in the backyard by a friend during the hunt. We played walk the plank over an old one ring swimming pool filled with stuffed crocodiles and there was a treasure chest pinata filled with candy to take home. All of the presents upon arrival were placed in another cedar chest with jewels draped over the outside. The party was a hit and the kids can hardly wait until next year's theme.  Most of these items were purchased at dollar stores, thrift stores or clearance racks over a period of three months so there was plenty of time to shop and I was able to keep the cost down to a reasonable level.