I don't know how I started this, but I've always kept eye contact in any situation. Astonishingly, you can tell a lot by how a person keeps eye contact.

Here's what I can personally tell from eye contact:

If he/she looks away after the first couple seconds or looks around, he/she is most likely timid or cowardly.

If eye contract is kept for at least seven - eleven seconds, make sure to glace at their pupils.  Dilated Pupils are often a sign of attraction.

If eye contact is kept for a whole conversation, this is most likely someone who is like me and can tell what you're thinking by doing this.

⚠Caution!⚠
Too much of this may make you seem creepy!
Use carefully!