Rent a tuxedo and a limousine; tell her you’re taking her out for a nice night, and do so - dinner at a nice restaurant with drinks and all that. Candles and shit. Before dessert comes, get down on one knee. Look her in the eyes and tell her how much she means to you - how you’ll always love and cherish her. Reach into your pocket, and pull out a Venus. Maintain eye contact. Then pop the question.