I have no idea why, but some of sweet things to say to your girlfriend works better when you are just starting out. Of course, you will always be able to tell your girlfriend that she looks nice, that she is pretty, that she is awesome and so on. However, if you have a chance, tell her You look absolutely amazing…
Believe me, in time it gets harder to tell these words. Probably because you are getting used to that wonderful lady of yours.