I just read Laura Vanderkam's 168 Hours and dog-eared like 10 different pages to jot down quotes and notes from. (I keep this file of Book Notes in my Google Drive to save tidbits from books that really left an impression.)
First of all, buy her book or order it from the library. It's amazing.
Second of all, the core thesis of her book—you have more time than you think you do—made me think of this passage from Leo Babauta's Zen Habits that I've kept handy since I read it last year. And I seriously think this concept is the key to time management.
Here it is: Curate your days.
What does that mean? Here's how Leo puts it:
Put only the best things in each day — don’t just let any junk into it. If you are going to read, be choosy, don’t just click on things because you run across them. When you’re going to choose your tasks, choose the important ones, not just the little busywork tasks. If you’re going to say yes to someone, make sure it’s worthy of being in your life. Would you pay $100 to say yes to this request? Would you pay $20 to read the things on your reading list for an hour? If not, it’s probably not worth it.
The idea is to take control of your time management by, literally, managing your time. Be very purposeful about what you spend each hour of your day doing. As you begin a new task, check your gut to determine if it's something you actually want to spend time on. Even when it comes to projects that you may feel you have no choice but to do, you may be able to delegate or outsource the work.
Dreading a happy hour you're certain won't have any networking benefits? Don't go this time. Overwhelmed by all the unread blog posts in your RSS reader? Clear it out and start over. In the middle of a book that's been a real slog? Stop reading it. Have a random free 45 minutes? Think purposefully about what you want to do with that chunk of time and do just that.