There many things you could give...
Can Give:

 Paper/Letter your feelings written on it. "Done This Before"

 Necklace [b](note that it should be silver not something that rust)[/b]  


 "Done This Before"

 Ring [b](note that it should be silver not something that rust)[/b] "Done This Before"

 A nice and simple but sensational hug "Done This Before"

 A sensational kiss "Done This Before"

 Give Her A Chocolate "Never Dones This Maybe It will cause their teeth to decay" 

Can Do:

 Go out together and have fun "DOne This Before"

 Watch Movies "Done This Before"

 Talk about how much you loved each other"Done This Before"
I think I dint lost anything... 
