RealSimple just posted an article called How to Be More Productive. These kind of articles pop up all over the place, especially over at Lifehacker; this one drew my attention because the items on the list are so innocuous, even pleasant. Get more sunshine, do something mindless, be present when a compliment is given, get physical, and work in small increments all sound manageable, and in some cases enjoyable. I'd love to take a sunny walk and do some mindless activity, and who doesn't like getting compliments?
The best tip is probably the one to break your projects into smaller, more manageable chunks; this is the mindset behind Getting Things Done and is also at work in the Pomodoro Technique. It's definitely motivating to cross smaller tasks off of a to-do list, especially when projects in graduate school easily growing to monstrous size in our imaginations. "Pass comps" or "write thesis" are impossible tasks to tackle in one go, but "read 2 articles" or "spend 20 minutes thinking about the next chapter outline" can be encapsulated, accomplished, and crossed off.