One of the worst bad habits to fall prey to would be oversleeping in the mornings. This habit becomes incredibly problematic when you have a strict schedule to adhere to. We're talking about everyone who has to go to work to pay their bills or go to class in order to graduate. Even if work and school aren't the obligations on your daily checklist, having to wake up for any reason at all means you can't oversleep through your alarms!
Plenty of people turn on back-to-back alarms in the mornings to encourage themselves to actually wake up and get moving with the day. If you're the type of person who accidentally sleeps through those alarms (or you continually hit the snooze button), your alarm plan probably doesn't make that much of a difference.
Breaking the bad habit of oversleeping on a regular basis comes down to you falling asleep a little earlier the night before or possibly setting yourself up with an exciting reward system. Think about cooking some bacon strips for yourself on a George Foreman grill the way Michael Scott did in The Office!