For my twin boys first birthday I selected an "under the sea" theme. I bought printable cardstock with a fish border and made the invitations on my computer. The color scheme was blue, green, and purple. Blue and green crepe paper streamers hung from all corners to the center of the room as did balloons.  I hung a fish net, purchased from a party store, from the ceiling and attached crepe paper sea creatures to it. I layered two table cloths (green and blue) on the cake table. A fish bowl with real gold fish was placed in the center of the table(I donated them to party guests after the celebration). Dried starfish (purchased from a craft store) and shells (gathered from the beach) were used as table confetti. I also found frog shaped beach balls(at a discount party store) and scattered them all over the floor. The toddlers loved them. To display the party favors(various ocean related trinkets wrapped in tool and tied with a ribbon), I covered a table with a blue table cloth and put blue plastic wrap over it to give the effect of water. I then placed some sand on top to look like an island. I constructed a treasure chest and had foil wrapped gum coins spilling out. I also placed some empty bottles on the table. Inside each bottle was "message" (I photo-copied a coloring book scuba scene and used the computer to add the message) that thanked guests for coming. Each "message" was rolled, tied with ribbon and a crayon, and put in the bottle.  Food included fish shaped cookies(made with slice and bake cookie dough), sandwiches cut with a fish cookie cutter(a raisin for the eye), blue punch with dolphin and seahorse shaped ice cubes, chips in sand buckets with shovels, and fish  crackers. A friend dressed like a mermaid and did face painting (ocean creatures of course) while guests arrived. She lead the kids in under the sea related games, read Rainbow Fish, and sang different sea songs. I had a CD with whale and ocean sounds playing while guests arrived. I also played music from the little mermaid soundtrack during cake time.    The fish crackers were placed in a fish bowl. The boys wore outfits with fish smocking on them. The party was a great success.