Have more sex. You might not be in the mood, but power through.
Have more sex in places you aren't supposed to. No, this doesn't mean you need to get busy in some seedy public restroom or dimly lit parking lot. Just move it out into the kitchen now and then, because once you have kids, you'll be relegated to your bedroom for the foreseeable future.
Have crazy sex. Enough about sex, amirite? Wrong! It's not enough to have more sex, but make it a little more exciting (try a new position, perhaps) before you start having very results-oriented, four-minute-long interludes that are as passionate as a firm handshake.