2) Be wary of interruptions
An interruption is much more than a delay in your to-do list. Researchers from the new field of "interruption science" have discovered that knowledge workers switch tasks every three minutes. And once interrupted, a worker takes an average 25 minutes to return to their original task, according to informatics scientist Gloria Mark.
Humans are built to be interrupted, since that's how we stay tuned to changes in our environment. But that means we have trouble pursuing our goals, and even remembering our goals, since our short-term memory is quite limited. Try to turn off the ringers and control the urge to check e-mail constantly if you want to get focused work done.