In "This Is the Happiest Relationship Ever, According to Science," Sara Boboltz at The Huffington Post diligently compiled research studies from academic journals about happiness and "success" in relationships. I present the most actionable or interesting findings here as canon, absolute rules to let the firm hand of psychological science guide us through the dread uncertainty of romantic engagement. The hand is not sweaty, did you notice? It's never sweaty.
Don't have weighty conversations by text;
Don't have a lot of mutual Facebook friends;
Don't be bored with life;
Don't, if you're a man, believe yourself to be more attractive than your wife;
Don't have sex within the first month of dating;
Don't lose interest in sex thereafter;
Don't have kids;
Don't be straight;
Don't hang out with too many divorced people;
Don't not go to college;
Don't not identify as a feminist;
Don't not consider birth order (first-borns pair well with last-borns).
Memorize and recite as necessary. If you can think of a tune and make it a song, that might be even better. The common wisdom is that you decide within about 90 seconds of meeting someone whether you're attracted to them, so try and make it a fast song. The cold hand of science apologizes for the double negatives.
Some of the other scientific predictors Boboltz found were pretty obvious, involving being similar people: Have the same sense of humor, have the same propensity for spending money, and have the same level of interest in alcohol. Other studies about likelihood of divorce have shown that twins share the same chances of marital success. So, don't have a divorced twin. If you do have a divorced twin, don't try to hurt or "get rid" of them. That won't help.