I'd say to just be with them and do something you two define as special. For my first anniversary we watched a baby video from each of us, had a small dinner, some sparkling apple cider, and some sexual relations afterwards. That was very special to me and him because we rarely get time like that to be with one another. But for others, it could mean something completely different.
Make her feel like she's the most beautiful and important person in the world for you...take her out on a special date full of surprises :)
Do something simple, but very well thought out, very personal for you both. She will love it. :-) PS: don't forget a bit of bling for her!
take em on a trip