To do: shower (don't forget to clean under your nails and in all the hard to reach spots), shave (or groom facial hair), brush and floss teeth, launder clothing, wash hands frequently. Personal hygiene matters, from keeping you healthy to keeping the women in your life, well, around you. It's not that most women will make a fuss if you skip the occasional shower or shave, but your overall personal cleanliness may be more important to the female persuasion than you realize.

Studies tell us that women evaluate men based on their qualities as a potential mate (and vice versa), but not with cues you may think. First, let's talk about how you smell. Smell is important to women, and not only that a man smells clean. Olfactory cues clue her in to whether or not you're healthy and strong. When push comes to shove, our genes are ultimately looking for the strongest mate, and how you smell -- how you naturally smell, not the cologne you wear -- can make a difference in how attractive you appear to the opposite sex.

Frequent bathing and clothes laundering will make a big impact. In fact, one study found that when a man's clothing smelled of pine, he was considered more attractive, more intelligent, more successful and more hygienic than if the clothing smelled of lemons, onions or smoke [source: Kerr et al].

And if you're looking to win over the opposite sex with something a bit more bold than clean nails, try wearing red -- a study published in the Journal of Experimental Psychology found that men wearing the color red were considered more sexually attractive by women [source: CNN]. Furthermore, when research psychologists at Northumbria University presented women with photos of men with various stages of facial hair -- clean-shaven, light stubble, heavy stubble, light beard and full beard -- the men sporting stubble were considered more attractive sexual partners, more mature and overall more masculine than the other men [source: Dobson].

Of course, the clean nails won't hurt either. Lowering the risk and spread of infection is also an important part of the personal hygiene package, from colds and flu to sexually transmitted diseases and skin infections. Not to mention that they're just more attractive than fingers sporting dirty half moons.

So what does it all mean? Some of it comes down to women preferring what they prefer -- whether it's a red shirt or five o'clock shadow. But if you look like you care enough to take care of yourself, chances are good that you'll apply that same level of care to the people close to you. And that's important to both women and men.