Changing careers is never easy. Half the world thinks you've lost your mind, headhunters say you'll never work again and your relatives contribute the old "I told you so" routine. But for many burned-out, bored or multitalented folks who are sitting on skills they're not getting a chance to use, changing fields is the only way to keep from losing their marbles. 

Regardless of your career-change strategy, never make these 10 mistakes:

1. Don't Look for a Job in Another Field Without Some Intense Introspection

Nothing is worse than leaping before you look. Make sure you're not escaping to a field that fits you just as poorly as your last. Be sure you do a thorough self-assessment first.

2. Don't Look for Hot Fields Unless They're a Good Fit for You

You wouldn't try to squeeze into your skinny cousin's suit, so why try a field because it works for him? People who are trying to help you will come along and do the equivalent of whispering "plastics" in your ear. Instead of jumping at their suggestions, take time to consider your options. Decide what you really want to do. When you enter a field just because it's hot, burnout isn't far behind.

3. Don't Go into a Field Because Your Friend Is Doing Well in It

Get thorough information about the fields you're considering by networking, reading and doing online research. Having informational interviews with alumni from your college, colleagues, friends or family is a fun way to get the scoop on different fields.

4. Don't Stick to Possibilities You Already Know About

Stretch your perception of what might work for you. Read job profiles, and explore career fields you learn about from self-assessment exercises.

5. Don't Let Money Be the Deciding Factor

There's not enough money in the world to make you happy if your job doesn't suit you. Workplace dissatisfaction and stress is the No. 1 health problem for working adults. This is particularly true for career changers, who often earn less until they get their sea legs in a different field.

6. Don't Keep Your Dissatisfaction to Yourself or Try to Make the Switch Alone

This is the time to talk to people (probably not your boss just yet). Friends, family and colleagues need to know what's going on so they can help you tap into that large percentage of jobs that aren't advertised.

7. Don't Go Back to School Unless You've Done Some Test-Drives in the New Field

You're never too old for an internship, a volunteer experience or trying your hand at a contract assignment in a new field. There are lots of ways to get experience that won't cost you anything except your time. A new degree may or may not make the world sit up and take notice. Be very sure where you want to go before you put yourself through the pain and debt of another degree program.

8. Be Careful When Using Placement Agencies or Search Firms

Do some research to be sure to find a good match. Ask those who work in the field you're trying to get into or other successful career changers for suggestions. Try to find a firm that knows how to be creative when placing career changers -- not one that solely focuses on moving people up the ladder in the same field.

9. Don't Expect a Career Counselor to Tell You Which Field to Enter

Career counselors are facilitators, and they'll follow your lead. They can help ferret out your long-buried dreams and talents, but you'll have to do the research and the decision making by yourself. Anyone who promises to tell you what to do is dangerous.

10. Don't Expect to Switch Overnight

A thorough career change usually will take a minimum of six months to pull off, and the time frequently stretches to a year or more.

Changing fields is one of the most invigorating things you can do. It's like experiencing youth all over again, except with the wisdom of whatever age you are now.