When love is the drug you’re looking for, what you’re physically after is elevated levels of dopamine, a neurotransmitter that floods the brain and makes you feel giddy as you fall for someone. So if you’re trying to steal someone’s heart, consider offbeat measures. “Try something novel,” says Helen Fisher, an anthropologist and the author of Why We Love (Henry Holt and Co., www.barnesandnoble.com, $25). “Go for a swim after dark or to an unfamiliar place. Exciting, different, or slightly dangerous acts will change the baseline levels of dopamine in your brains.” Once you’ve won the heart, the trick, of course, is keeping it. Harville Hendrix, a marriage counselor and the author of Getting the Love You Want (Owl Books, www.barnesandnoble.com $14), counsels spoken appreciation. “Before my wife and I go to sleep, we name three things we appreciate about one another,” he says. Frequency is key. Saying “You were great to make coffee” on several occasions beats a onetime “You’re the greatest.”