The first thing I do with first screens is casually specify a specific time and a few other details like dress, specific directions etc. Its amazing how often these details are flat out ignored by the potential hire. I'd say 80% of people get scratched over some pretty basic almost mindless stuff. And people, if you're looking for a job - clean up your Facebook/Twitter feed. Pics of you with a shotgun aimed at your neighbor's dog, or pics of yourself drunk in your truck waving a pistol generally don't go over well. And good god, don't post your own drunken, idiotic rap rhymes fraught with misspellings and racist, homophobic or sexist ramblings. People are just f'n dumb..