The best way to impress your girlfriend is to be observant and always comment on how nice her new hair-do is, or the new shoes she is wearing etc etc, they think that most men don';t notice these things so when you do they are impressed. And compliment her on her best features.
Hey look me being serious.
yea but I think fearless already ha a relationship
some things I did for former girlfriends include:
-sending her 75 roses for her birthday (she liked roses a lot)
-taking her out for a romantic seaside picnic just for fun
-giving her a white rose each time we had a date
-sending poems (never gone wrong with that)
just things like that
but as lara said be yourself dont fake it
and as corran said pay attention to the lil' things dont look for special date to do things like valentine or x-mas or stuff just do those things on normal dates as well