How to refuse a proposal Jane Austen style:
“Upon my word, sir,” cried Elizabeth, “your hope is rather an extraordinary one after my declaration. I do assure you that I am not one of those young ladies (if such young ladies there are) who are so daring as to risk their happiness on the chance of being asked a second time. I am perfectly serious in my refusal. You could not make me happy, and I am convinced that I am the last woman in the world who would make you so. Nay, were your friend Lady Catherine to know me, I am persuaded she would find me in every respect ill qualified for the situation.”
Taken from Pride and Prejudice by Jane Austen.