Presentation is the main thing to focus on when making dinner for your date. It is no different than a magician executing jaw dropping illusions. The way the meal looks often times is more significant than the actual food.
First, make it appear effortless.
So you've been cooking endlessly for the whole day, you don't want her to knowing this. Tell her the dish just came to you and that it was nothing. Remain slick and humble. It will go a long way.
Second, present your gastronomical creation in the best possible light.
You're not in elementary school anymore, so throw away those plastic sporks. Try being a grown up and use heavy silver ware and good, solid plates. Bonus points if they match!
Third, no matter how many times she offers, do not let her clean up or do the dishes.
They'll be there in the morning. For now, let's focus on you're date...