The best was when I was sun bathing on a dock and felt some wet drops on me, I looked up and saw my first love holding a lily from a lily pad that he picked for me. The second was when my true love and I were out to dinner and when I came back from the restroom I was surprised to find he hid a gold locket under my napkin. So I guess I find surprises romantic. I also loved the uniqueness of the lily.
Flowers for sure, a little old fashioned but it's very romantic either way. Surprises every so often, like making dinner for her when she doesn't know. Just doing special and little things all the time I think goes a long way.