My youngest son loved balls (it was his first word, it was all he played with) so it was easy to come up with a ball birthday party for his 1st. This was a large party (all our family & friends were invited, as with all our 1st birthday parties).
I found every ball I could... I bought a bag of play balls (the ones that go in ball pits) at Toys R Us and filled a clear bucket for the centerpiece. Then basically put balls wherever I could. I got kick ball- size playground balls at the dollar store that doubled as decorations and favors (this was a huge party...my husband's family is very large...there were a lot of balls around).
I found the "paper lanterns" at a party store, they actually had graduation caps hanging off of them (which I cut off) and no colorful ribbons to hang them from (which I added), don't be afraid to alter something to make it work for you. His banner was just letters I printed out on the computer, cut out, matted with colorful paper, and strung together with paper ribbon.
This cake I actually didn't bake, just decorated. I ordered a pre-made cake from Sam's Club, and had them just frost it white, smooth, with no borders (I think they thought I was a little crazy). This made it really easy to just add the bouncing balls and dash marks (thanks to Martha Stewart for this design) and it tasted great.
We don't do meals for big parties, so we plan it for mid-afternoon and serve snacks. This party was very laid back.
Veggies & Dip
Cowboy Caviar & Tortilla Chips
Lil' Smokies in a blanket & Barbecue Sauce
Fruit & Cream Cheese Dip
Ice Cream & Cake