This may sound extreme, but for me the trick was to limit the amount of time I allow myself to roam freely on the Internet. I only allow myself 1 or 2 hours per day because honestly it's a soulsucking waste of time unless I'm using it for schoolwork, or to learn something specific that I have preplanned. I do allow myself unlimited phone time but it's not that big of a distraction compared to my computer.

Secondly, college lectures are meant to be heard after you read the material, and most professors teach under that impression. If you already know the material it's much harder to get lost if you daydream, and lecture will normally clear up any problems you've had while reading.

Thirdly, use a to-do list, and a daily planner. It may sound awful and hard, but it's really easy. Just put things in your to do list with a due date on them, then split up the work over how many days you have to do it. I normally try to finish a day early if possible to allow for emergencies. Let's say you have something due in 3 days. You approximate and split it up into 3 chunks, then plot those chunks into a time slot, let's say 4pm-5pm if it will take an hour per chunk.

This is challenging to do when you first start off, but the secret of productivity is habit building. You waste time on the Internet not because you made a conscious choice to get on the Internet, but because it's a habit and automatic. You can build good habits and slowly replace them with bad ones.

For me, I always work on my homework for about 2-3 hours after I get home, I do it everyday, and I work hard, and it's actually enough to keep up with all my computer science classes and gives me the rest of the day to just stare at a wall if i please.

You gotta think of doing time management as being in sinking little boat. If you wake up everyday, and use a bucket for a couple of hours in the morning after breakfast, you won't sink and honestly life won't be bad. If you procrastinate though, your boat will almost be sinking constantly and you will have to do frantic efforts to save your life every couple of days and you'll probably get a bunch of your stuff wet.