I like looking at people. Looking into people's eyes, rather. The simple act of making eye contact - it expresses so much, yet reveals so little.
For example, when you're eating (say with a pal) and you look around. You happen to cast a glance at the pretty lady sitting at the next table. You make eye contact. She brushes her hair self-consciously.
Does that constitute flirting?
Doesn't matter. You think, hope, rather, that she Is flirting with you. And she probably is.
(Oh pummel me with comments, women. :D)

I'll really like to know what goes on inside a girl's mind when a guy looks at her, rather, into her eyes, actually.