Setting the scene
As far as decorating the room or yard, keep it simple! A bag of balloons that you blow up and tape to the swingset or backs of chairs, plus a few rolls of streamers from the dollar store can set the scene perfectly.
If you are interested in an inexpensive source for custom, coordinated décor, Etsy is a good source for party printable packages. You pay for the download, then print everything yourself. (You can do plain paper printing for free with your King County library card — to print on cardstock, you will need to head to a print shop.)
This $23 package from Etsy includes everything you could possibly need: hats, invites, cupcake wrappers and toppers, photo booth props and more. .
If your party theme is based on a cartoon character or an animal, don’t buy an entire set of paperware emblazoned with your character of choice. Plates with the smiling face of Dora the Explorer are great, but the reality is they will end up covered in cake and in the trash can. Instead, choose one item that represents your theme, such as a tablecloth, mylar balloon or centerpiece, and then add paper plates, cups and napkins in a coordinating, solid color.
Better yet… go green and use your own dishes! (Plastic dishes for the younger set, of course!)