If you know her dress size...what kind of material she likes...and her taste in colors and fashion, you could buy a nice dress and then take her out to her favorite fancy resturant that she hasn't gone to in awhile.
And if it's too hard to figure her fashion tastes...tell one of her friends to take her out and look for some dresses for a special occasion (make one up, but choose it wisely...but don't make it a funeral) , but tell her friend to not let her buy anything. Then get the info and buy the dress she wanted the most. And before you get the dress...make sure she has a pair of shoes that'll match it because buying shoes for a woman is just out of our ability.
It could get very expensive though, dress..shoes..fancy dinner..drinks.
And you have to downplay the whole thing...like tell her you want to stay in and cook (you cook, so she doesn't make a dinner and find out your taking her out).
