Our son chooses his party ideas immediately following his last birthday so we usually have quite a while to plan things. This year is was Outer Space. We started with fun alien invites- I stamped the outside with spaceships and stars on tin foil.  The inside said:  We are having an out of this world party for Devon's 6th birthday.  Please come for cake and ice cream. If you can't come please RSVP to the mothership at XXX-XXXX. I painted some styrofoam balls different designs, some with fun foam rings" for planets that we hung with fishline all over the place for decorations. We also had some really great NASA posters from my science teacher aunt.  My son and I made spaceships to using a plate and a bowl we colored them with Sharpie markers and used rubber cement to glue it together.  The kids used them like frisbees in the backyard trying to toss them into a box- mostly they just went everywhere!!  We had a lot of younger siblings at the party so we decided not to have a pinata- instead we had a meteor shower.  I took all the little toys and candies and wrapped them individually in tin foil. My husband climbed into our treehouse and tossed them into the air.  You should have seen the kids scramble!! For "specemin collection" each of the kids got a Pringles can that I had cleaned out spray painted black and covered with star stickers. He threw them all over the place to get them really spread out and I made sure I had a lot of them so no one was short changed. I actually may have gone overboard each kid could barely shove them all into their cans.  :)  Better to many than not enough I figure.  We made a really cute 3-D rocket cake that I had saved out from the now extinct Rosie magazine.  You used different sized tin cans (emptied of food and washed) to bake the cake parts.  You go from coffee can size all the way up to a pineapple juice can with a pointy sugar ice cream cone top.  You used regular cake batter and fill each can halfway to bake.  They are kind of a struggle to get out of the can in one piece but then you stack them (use the long wooden skewers to get them attached to each other) use Hershey's chocolate bars to cut out the upper and lower fins.  The whole thing was frosted in blue and white. We wrote USA on the pointy part and Devon 6 down the side. We also used fruit streamers (red) to make stripes on the rocket. We have big parties so we also used cupcakes.  Our son wanted chocolate with chocolate icing (that didn't really fit the theme very well) so those we decorated with the premade CakeMate candies- there were stars rockets planets and robots.  Then he also wanted yellow & green cake (his 2 favorite colors).  How do I do that??  Well we used lemon cake mix and green frosting- to of course make aliens!! I used green fruit streamers pieces stuck into the cupcakes to make antennaes and used tiny candy eyes and drew the mouths on with gel. A friend helped me to make suckers- we had robots aliens & rockets in green.  They were a big hit.  For the favor bags we had alien rocket launchers that I made from kits (OTC) glow in the dark sticks planet and star stickers sheets pop rocks one each of the suckers we had made and green Yogo streamers.  I also made each of the kids their own space logs: I printed up sheets from www.learningpage.com. They have a whole section of space related worksheets and information sheets.  Since our oldest guest was 7 I limited each book to a few pages about the solar system and then a bunch of dot to dots coloring pages tracing lettersetc.  For the older kids each book ended up with 22 pages for the younger siblings I made the pages a little easier and the books were 14 pages long.  It is a great website for printables and they have different sections for preschool kindergarten and each grade level so it was easy to pick things for the right ages. It was a really fun party to plan.  The books did take some effort but the parents have already commented how the kids dove into them the very next day!! Sucker making took 1 evening but again were really well received and every guest ended up with one not just the kids! "