So I'm just throwing it out there: men should not wear sandals. ever. I know that guys aren't really concerned with fashion, but this is one thing that should be obvious. Think of it this way: you button up a shirt to conceal chest hair. For that same reason, you should cover your feet. No one wants to see hairy feet. No one finds it attractive (unless there is some sort of fetish group I'm unaware of).
I do feel bad because I know that sandals are super comfy in the summertime and wearing sneakers can be a pain on super hot days. I feel for you. But women go through waaaaay more obstacles in life (read: every month when our girly parts virtually go crazy). So, this is simply your cross to bare.
So guys, if you ever want to meet a woman, or just don't want to look ugly, please ditch the mandals.
And no, adding socks does not make them more appealing.