According to Amazon's Jeff Bezos, there are two types of decisions. Type one decisions are easily reversible. If you don't like the outcome of your choice, you can just change course. The second type requires more careful decision-making because these can't easily be undone.

Unsurprisingly, Bezos warns that the biggest danger with the first type is being too slow to make them. But the second type can be life or death for a business (or in the personal realm, for your happiness). So what's the best approach for making these truly tough calls?

Top VC Brad Feld recently offered an intriguing suggestion on his blog. His idea: if a truly difficult decision isn't reversible, you'll need to take your choice out for a month-long test drive.

Try on your toughest decisions

"I've made a lot of major decisions in my life--both personal and professional. For the professional ones, I've come up with an approach that I now use consistently. I try on the decision for a period of time--the more significant the decision, the longer the period of time. For the really major decisions, I try them on for 30 days," Feld writes.

He goes on to offer an example from his personal life when he was burnt out on investing following the bursting of the tech bubble in 2001. Should he quit his work with Mobius Venture Capital and take his career in a different direction? Here's how he went about making the call:

"I woke up one morning in February 2003 and decided to spend a little time each day pretending like I had quit Mobius. I allowed myself to think about it twice a day--when I first woke up and when I went to bed at night. During the day I continued to work my ass off on everything I was doing for Mobius. But I gave myself two periods a day where I contemplated what a different work life might look like."

During his two daily sessions of reflection, he wrote down his feelings. Was he relieved at the prospect of quitting? Sad? After a little while, a pattern emerged, he reports.

"I didn't dislike the work, even though most of it was not very fun. I felt a strong sense of responsibility for Mobius since I had helped create and contribute to the mess we were in," he explains. "But I didn't feel engaged in the decision making that we--as a firm--were doing to get out of the ditch we were in."

After 30 days of this, Feld "had a clear understanding that quitting Mobius was not the right answer... Instead, I needed to commit to engaging completely and taking responsibility for the whole firm, not just my corner of it." It turned out to be not only the right call in this individual case, but the right approach to hard choices for Feld.

Maybe a similar mental "try-on" would work for you too. Or, if you're looking for another approach, other experts have alternate suggestions for how to approach life's toughest calls.

What's your strategy for confronting weighty and irreversible choices?