I'm not an especially productive person, but here's a series of steps that works for me:

Make a to-do list of EVERYTHING you need to do.
Make yourself some tea or coffee and drink it.
Keep your to-do list open and visible right next to your workspace.
Set yourself a number of items from the list that you MUST complete that day (I usually try to get 3-4 things done, but it depends on how time-sensitive the tasks are).
Reward yourself after each one. (Optionally, you can make the rewards more awesome the more tasks you complete – e.g. for the first task, you get another cup of tea, but by the time you get to the 5th one, you get to take a masturbation break. Or whateva.)