Sometimes the simplest thing is the most meaningful. Is there a special place, moment, event that is significant and cherished besides the wedding for you? Plan a day/evening full of events and refreshment reminiscent of a very special time for the two of you.
A beautiful blank card or handwritten note on nice stationery saying why you are happier one year later than you were on the happiest day of your life a year ago! Place this with one stem of a favorite flower, a candle, a little music, favorite beverage and snack and it’s a very romantic moment.
Anything simple you’ve discussed that you’d like to do, but never have made the time for? This is it - maybe a picnic and day at the zoo. Maybe she likes concerts/ballet/theater and you don’t and balk normally at those things. (I’m not saying you do or don’t mind you!) Get tickets to something you know would mean a lot to her but not break the bank.
Don’t work at hitting it out of the park on the first anniversary - remember you will be setting the tone for years to come and you may want to build on it every year as you are able. Or you may find you like the simple, alone time where you forget all the material trappings of what is fantastic and find that those little special things that sometimes get lost in the day to day are what brings extra pleasure in remembrance of such a special day.
Hope some of this helped. Congrats and many, many more!