I tend to use mascara mainly since it can be subtle or more dramatic and since I have glasses, it helps bring out my eyes behind them. Mascara is conveniently easy, not too many colors to choose from, not too much effort required to apply, and it generally looks good on everyone. I've found that my attractiveness increases significantly with just adding mascara, so I find it worthwhile. If there's a feature you want to play up, it's good to find a nice way to enhance it.

Light makeup, as far as I can tell, usually refers to a little mascara, a bb cream or light foundation, and maybe a bit of lipgloss or tinted chapstick.