Men, in general, have very few "mandatory" grooming habits. The gist of what they MUST do is shave (and sometimes only half their face, depending on the style of their facial hair), brush their teeth, wash their hands, shower, cut their hair. All other things are just for fun - like coloring hair, growing fancy facial hair, shaving body hair and so on. Because of this short list of requirements, it ultra-disgusts me when men have the hated bad habit of not clipping their fingernails. It isn't difficult. You simply take out the fingernail clippers once a week and voila! you're finished. If this easy all-in-one step is skipped in a man's short grooming regiment, his hands will quickly turn into a hideous combination of feminine/creepy killer/cocaine addict. Surely all men want to avoid this look - as it doesn't look good.
Somehow most women manage to get their hair colored, shower, shave (in more than one area), paint their nails, get pedicures, whiten their teeth, do their hair in fancy styles, dress super cute, wear uncomfortable shoes and ... the list never ends. Sure some of these things are fun and we women do them because we love it. However, some of it is a pain in the ass (like plucking/waxing our eyebrows) and we still manage to get the shit done.
So please, men out there, cut your fucking fingernails.