Depending on the type of hat you are interested in, here's a link on the gallery to my search for Easter bonnets:
Easter bonnet - Homemade Cards, Rubber Stamp Art, & Paper Crafts - Splitcoaststampers.com
If you look through the pages you will find lots of different decorated hats for ladies.
If you are wanting a different style, for example, cowboy hat, put that in the search box.
Have fun decorating your hat, hope you find lots of examples to inspire you!