For my son's 1st birthday I went with a balloon theme because he really isn't into any characters yet and all kids, no matter the age, love balloons.  Invitations:  Use a balloon, instead of the traditional card. Blow up the balloon (don't tie off), use permenant marker to write info., then deflate and place in envelope. Your guests will be excited to blow up their fun invitation. Activities: I had a ball pit usinga blow up pool and the plastic balls you can find at Walmart, Target, or Toys-R-Us. I even asked my neighbors if I could borrow so I wouldn't have to spend more money. My 13 year old had the job of counting the number of balls I borrowed andshe putthem back in the bag too.  The babies had funin the balls, even the toddlers and preschoolers had fun.  They enjoyed bouncing on the edge as much as being inside.  I also bought a Balloon Art Project kit from Micheals Arts and Craft store.  The kit includes balloons, stickers for eyes, hands mouths, and cardboard feet so your balloon person can stand.  Write thier name on the bottom. Even my 13 year old couldn't resist making one.  I also bought a kit to make twisty balloon creations that clowns make. A neighbor took charge of that and made the kids all sorts of hats, swords,and animals. Of course blow up some normal balloons for the kids to kick around, run threw and at the end of the party.... pop!  You can also organize more structured games too. Such as over the head-- under the legs relays; first to kick a balloon to a target; longest person to keep balloon from touching the ground; even water balloons for outside games if you'd like. Party Bags:  I included balloon squawkers, punch balloons (Party City), balloon powered race cars (Oriental Trading), balloon whistles (OT), bubbles, chinese yoyos, blow pops and other candy. They also got bring home their balloon person and twisty hat/sword.  Decorations: Balloons of course! I taped two helium balloons on each table with chocolate kisses for centerpieces,  I also taped balloons in variousplaces on the walls, around fire place, on high chair.....  I bought balloon plates, napkins, and a banner. Party City has banners for several ages, even 1st b-day.  Food: For the kids I just baked chicken bites, and for adults I served meatball sandwiches. Meatballs from Costco in freezer section and Ciabollo rolls there too.  Add your favorite spaghetti sauce and cook in croch pot for several hours. Serve with provolone cheese or any you like.  It was so easy. I also had chips, crackers,dips, fruit, veggies and grandma made pasta and potatoe salad.   Cake: My son's cake (the one he destroyed)was free from Vons with the purchase of a sheet cake. It was decorated with balloons of course.  This theme works with many ages and is fun and easy.  I hope you find it helpful.