I'm actually enrolled in a psychology course right now and current research shows that pressure due to procrastination actually does not allow to work harder or more effectively. According to my text, studies show that procrastination has a negative impact on quality of work performance and that time management is actually a better predictor of college GPA than SAT scores. The book suggests some time management techniques as well: monitoring your use of time, clarifying your goals for projects, planning your activities using a set schedule, protecting your work time by getting rid of distractions, and increasing our efficiency (tackle one task at a time, handle papers only once, group similar tasks together, making use of your down time).
I was a chronic procrastinator, and I've found that breaking tasks into smaller chunks works wonders for me. Also, making sure I'm in a quiet area. No music, TV, or anything like that. I'm less stressed and I'm more focused on the task at hand. And since I'm doing them in small chunks, I can easily spend 30 minutes to an hour on something and then move on to something I would rather be doing.
Hope that helped a little! :]