If my life's gonna end 3 days from now, I'd go normally for the first 2 days.
The third day will be spent cleaning up potential messes. Like creating a will, a last letter, clear my website status, post a positive last blog/twit, take my girlfriend on a last date.
The last thing I'd like to do is drink a cold glass of milk, and sleep early. It's the best way to die for me. No pain, no suffering. Just close your eyes willingly and put your body at ease.