
1. Learn how to say no to extra stuff
If you're anything like me you have your hands in many pots. You may feel like becoming a student again will free up some time and, as a result, you may seek out more pots. This is very rarely a good idea. Three classes a week (this is after your core courses; before that you may have four or five) may not seem a lot - add 6-10 hours per class of reading and 20 hours of Research Assistant work every week and your free time may not seem that free anymore. There will be a lot of opportunities to get involved in extra stuff - I suggest you make sure you have a handle on your day job before you make any commitments.
2. It's not enough to read the syllabus - talk to your professor and students who have taken the class before.
The worst decision of my academic career was made based on a four-page Word document. To say that syllabus was misleading is like saying the center of a raging volcano is a little warm. A bad class can be a nightmare. A bad doctoral seminar can be hell on Earth. Bad teachers do get tenure - it happens more often than you may realize. Be. Very. Careful.
3. Make every seminar a potential chapter in your dissertation.
Don't waste your time taking doctoral seminars that won't have any value towards your dissertation. The name of the game should be efficiency. At the end of these seminars you are required to write 25-30 page papers that require lots and lots of thought and effort. Not being able to do something with that final product is a tragedy - you don't have the time to waste (well, you might, but why do it?)
There's more to come - watch this space!