Choosing a theme for your child's first birthday makes it easier to plan and purchase the items that you need. She may not yet be able to choose the theme herself, so you'll have to do it for her. Look for inspiration in her favorite storybooks, toys or characters on TV.
A princess theme is an easy choice, since you can always find princess-themed party supplies. Use pink as the primary color and give her a little princess hat--at least long enough to get the pictures taken. Decorate her high chair with pink balloons and fairy-tale-themed streamers specially designed for high chair decoration.
Abby Cadabby is a favorite girly character on Sesame Street. She is famous for casting spells to do magic, though she often gets things wrong. Pass out magic wands for the children and ask adults to make one wish for your daughter's birthday. Collect these wishes and put them into a book that she can look at when she grows up. You can find paper plates, napkins and balloons that all feature Abby Cadabby.
A favorite animal can also make for a good theme for a first birthday. If she's into cats, bunnies or horses--and many girls are--use that as a theme. Plates and napkins feature cartoon versions of these animals. Purchase a pull-string pinata in the chosen theme and play Pin-the-Tail-on-the-Animal.
Ladybugs and Butterflies
Many girls find real bugs icky, but ladybugs and butterflies often make the grade. Do a craft where the kids glue dots on the backs of the ladybugs and hire a professional face painter to create butterfly designs on the children's faces.
Use fairies as a theme for a little girl's birthday party. Purchase pre-made fairy wings for the children, then have them decorate them using watercolor paints and glitter. Tiny foods, like mini cupcakes and fruit cut small, play into the theme.
Your daughter's first birthday really is all about her, so you could simply use her as the theme. Purchase plates from a company that will place your daughter's face on the plates--sometimes along with a cute princess hat. Serve only her favorite foods and use decorations in her favorite colors.