If you say "yes" to most things that come your way, you may be a nice person, but you're probably not a very happy one. Establishing good boundaries is a big challenge for many people. And it is an essential time management skill for creating a successful professional life.

Here are a couple of key tools for establishing healthy and effective boundaries:

- Set specific periods of every day when you take calls and answer email. Don't become a slave to email, the phone or IM.

- Learn how to say "no