For my son's first birthday we decided to do a Rubber Ducky theme. I started off by making personal invitations by snapping a picture of my son in the tub w/lots of bubbles and some inexpensive rubber ducks. Next I edited it on my computer with the wording "rubber ducky your the one..who makes _____ birthday lots of fun! For decorations Im planning on using those ducks to adorn the tables and use blue/yellow/white balloons.  Im using some duck and bubble stickers I bought at a craft store to decorate some punch pitchers which im planning to fill with blue punch with some mini rubber ducks floating in them. For the birthday cake I found a 3d Rubber ducky cake pan that I'm planning on setting on top of a larger round cake decorated in a coordinated bubble theme. We are using some large galvanized wash tubs filled with ice for drinks.  For party favors I purchased online some cute party favor bags with ducks. Im filling them with a bottle of body wash (travel size or free samples from hotels work) which I removed the front manuf. sticker and wrote "ducky wash" with perm. marker and used some duck bubble stickers to decorate. I included a bath puff, bubbles, a rubber ducky and some candy.  If the weather permits a bubble machine from a local florist/party rental place will help set the mood in our backyard.  A inexpensive kiddie pool with floating ducks(oriental trading)with numbers on them can be used for a bobbing for prize game with each number corresponding to an inexpensive water/pool toy from a dollar store. If the weather is really nice ask your guests to bring there swimsuits for the kiddie pool.