I agree with lyrwe. Especially, if we're talking about a situation that is likely to make the guy come off as creepy, i.e. Isolated or late night. A random make stranger trying to talk me (without an obvious purpose, like asking for direction, and possibly even then), is going to make me grip my keys or knife and speccing out where I'm most likely to find help if I need it.

I feel that most non-creepy guys would mind their own business. I like the suggestions of obviously focusing their attention elsewhere.. A male stranger taking unusual interest in me (especially anyone larger than me, which is nearly anyone) is going to set off my alarm bells.

To note, I severely dislike walking alone late at night and avoid it whenever possible.