1. Work with the marking criteria next to you - Most lecturers will give you a copy of the criteria that they are going to mark you against, and by working with it along side you, you can see what they're after and make sure you get it.
2. Break the assignment into small manageable chunks - By breaking the assignment into smaller more bitesize chunks, you'll find that you can complete even the most unmanageable of tasks. I did this with my dissertation and it became a whole lot easier.
3. Take Regular breaks - Don't overwork, you'll get bored. It's easier to take 5 minutes out then go back to it.
4. Work with other people - Study or write with people around you who are also writing (even better if they're writing the same essay as you...) you'll find that you write more and get yourself into the right frame of mind.
5. Remove all distractions - Take away the distractions; the TV, facebook, twitter or tumblr. The sooner you knuckle down and get started, the quicker you'll be finished!!
6. Avoid working through the entire night - By the end of the night I'm guessing the writing you write will become harder and harder to understand and less and less like the work needs to be.
7. Set an 'internal' deadline - Set yourself a deadline before the actual hand in and try and get it done for this date. This just saves the stress of getting to the hand in office on time when you've been up all night trying to get the essay finished.
8. Have food and drink to hand. - When you're working through an essay there is nothing worse than finding you have no food that is easy to cook. Exams and assignments are the perfect time to have ready meals (I tend to avoid them the rest of the year...)
9. Ask for help sooner rather than later - If you need help from your lecturers, don't leave it until the week before because that is when everyone else will want the help and they just won't have time for everyone. Plus they might just outright refuse to help to close to the deadline...
10. Don't leave it until the last minute - Avoid the stress and get it done early. Its better to have the bulk of it done and have time to edit, rather than trying to write right up to the last minute.