Today's technology is dominated by apps that encourage breathless spontaneity. You're encouraged to share anything and everything as quickly as possible. That's fine when you're dealing with friends and family, but it's very dangerous in the business world.

Any email, post, tweet, or text that's off-base, off-color, or off-the-wall can instantly ruin your reputation. Before you know it, an unguarded thought or imprudent remark becomes who you are in the minds of the people who count.

For example, a salesperson recently contacted me because he worried that he might have alienated a customer by leaving a comment on his corporate blog that contained some harsh criticism of the company's corporate strategy.

The salesperson, to his credit, is usually calm and collect, but in this case, he was reading the customer's blog while in a lousy mood, due to some problems in his personal life.

I have no idea whether his flame-on actually burned bridges, but there's no question that he made his job a lot harder.

Here's another example. I once worked with a marketing new-hire who was bright, talented, and personable. Even though she'd been working at the facility for less than a year, management had already marked her for promotion.

One evening, while out partying, she sent a slightly sexy selfie to a friend with the jokey subject line "Free Sex!" Unfortunately, she accidentally copied the email to 400 of her co-workers and her career at that company was effectively over.

Neither of these examples is unusual. Every day, people screw up their personal brands by not following this absurdly simple rule:

Never go online if you're angry, upset, or otherwise impaired.

By "never go online," I mean don't use any program that is capable of automatically sending or posting anything. If you simply must write something, write it in an editing program that stores it as a separate file, like Microsoft Word on the PC or Notes on an iPhone.

Then, later, when you're not impaired, consider whether you want that document, comment, or tweet to become public. Most of the time, you'll find that what you've written is either inappropriate or needs heavy editing before anyone else sees it.

This technique has personally saved me from at least a dozen situations in which my opinion, expressed in the unvarnished original, could have easily killed an important business relationship.