Your engagement is the first step in the rest of your life with this woman. Take the time to make a plan — even a quick plan — and do it right. You don't want to regret not having done something that you would have, if only you'd thought of it. Your girlfriend doesn't want to hear after the fact that you would have had champagne and roses for her, but it was kind of a lot of trouble and you were tired. Remember: You get one shot at this.

Hit the Showers!

Don't ask her when you're unshaven, kind of stinky, really tired, and generally unkempt. She may be your best friend in the world, and she may see you like this all the time, but this moment is going to be etched in her memory forever. Clean yourself up a little.

While you don't have to think of this as putting yourself on display, maybe you should. What if the tables were turned, and she came to you, in a dirty T-shirt, not having combed her hair all day, looking like she was completely unenthusiastic about the topic at hand — namely, taking you for her lifelong partner?

This is probably an unfair analogy, as many men truly don't ever care whether their girlfriend is showered or not. She looks good to you regardless of her cleanliness. Women, however, by and large, do care, especially at moments like these. No one is suggesting that you need to have a manicure and buy a tuxedo for the occasion. Just make an effort to be clean and coherent.

You've Been Out Painting the Town …

You come home to an irate girlfriend after a wild night on the town, who has told you time and again that she's not going to put up with your rowdy ways anymore. She's ready to call it quits when you hear yourself saying: “I'll change if you marry me!”

Though this might be the most heartfelt statement you've ever made, the situation is just not right. Whether either of you realize or admit it (you both feel that she's completely justified in her threat to walk out — and she probably is), this is a proposal made under duress. Things may work out swell; but it's just as possible that you will revert to your old ways and learn to hide the evidence better.

A proposal should be made in a sincere way, and because you want to be with her for the rest of your life — not because you're afraid she's going to walk out on you. (There's a big difference there.) Presenting a proposal in this manner also means that you're promising to amend your errant behavior right away — and now you've got even more on the line if you mess up. Granted, it's the kick in the pants some men (and women, to be fair) need to move forward in their lives; but for others, it's like living life in a pressure cooker.

You've flat-out told her that you're going to change if she marries you — which carries not just an implication, but the promise that you're a new man, starting now. If you mean it, great. Best wishes. If you know you can't live up to this expectation, you need to tell her — and the sooner the better.

Pass the Chips … Oh, and Will You Marry Me?

This is going to be one of the most exciting things your girlfriend has ever experienced — the realization that you are, indeed, The One. Even if the two of you have been talking about getting married for months, the proposal is going to knock her for a loop. Treat it like the big deal that it is.

You may be the world's most nonchalant man, taking everything in stride because you despise hoopla. That's fine and well — but you don't have to be a party pooper your entire life. Put your feelings aside for this moment and act excited about becoming engaged.

Avoid the casual mention (as you're walking out the door in the morning) that it would be really nice if she would marry you. Don't toss the ring her way as the two of you sit watching the game on TV. Leaving the ring with a note attached to it (“Hey, I was thinking … let's get married. P.S. We're out of milk”) is completely unacceptable.

This is a milestone in your life. Give it the allotted time, attention, and respect that it deserves. You'll regret it if you don't.

Your girlfriend will fall in love with you all over again when she sees that you — the man with very few emotions — were able to work up a little excitement over the idea of asking her to be your wife.