Well, you can always keep a man's interest by being slutty in the bedroom. Though it helps if you're prepared to be slutty in the kitchen and in the bathroom, in the car and everywhere else. Flip his kinky lid, so he thinks twice before moving on.
But in all honesty, you don't have a problem. Anyone who can get through five relationships in a year won't get stuck on the shelf. It's when you're not meeting anyone that you should worry.
The best dating advice I've heard was from an old society queen I met while travelling in India. His aunt advised debutantes to "collect, then select".
Had you dated five men simultaneously (and I don't necessarily mean slept with them), you would have handled each with irresistible aloofness and assurance, confident that others waited in the wings.
You could have strung them along for years while you made up your mind.
Pressure in the initial stages will kill a relationship. Focusing too much on one person and being too strict in your criteria of what qualities a man should have will sabotage your chances.
Enjoy yourself instead. Play the scene and meet people; be open-minded and have fun. Be the belle of the ball with a choice of suitors.
And when one stands out from his competitors, having stuck around to prove his interest, he will be your pick - and a wise one, too.
The game of love is most easily won when it's rigged in your favour.