If you do one thing today, check out the link below. It's from a great ad blog, focused on students called Makin' Ads. This particular post is about not closing the loop when making an ad. Some ads over explain the ad, while others leave you wondering WTF? You need to aiming to leave just enough unexplained that the viewer happens upon an 'Ah-ha' moment.
The best ads will engage the viewer. If you over-explain it, or confuse them, they won't be engaged.
Click here for more.