Ok here is an idea
Try cooking something and make it a great meal like a deluxe meal with starters and not just 1 plate
Take her to an isolated place especially if you live in a city
Take her into an isolated field lightless
Take some candles and soft music (small stereo)
Try to make it on elevated grounds having a nice view
AND DO IT BY SURPRISE!!!
tell her ur coming by at 10 lets say and go with ur car/bike and then take her
make it a surprise and take a blanket just incase you get lucky

AAAAAAAAND try flowers and all
BTW KEEP THIS HIDDEN THROUGH UR DRIVE DONT LET HER SEE FLOWERS AND ALL
also take some fragrance to make the place smell good but not too strong
and get music for you two to dance on the sound
and also bring flower leaves to make the place look good
AAAAAAND it could be also a great idea to start the fire and grill stuff over there too
thats my idea of romantic night not that i can squeeze that much for my gf as she doesnt like cuddles or anyhing shes quite un-feminine
Best Regards
Hashem