We all have times when we're feeling run down and pessimism strikes. "Oh, this will never work..."

Next time it strikes you and you get hit with a malaise, try this out:

Write down everything you're worried about going wrong.

Yup, in your mad pessimistic dash, just put everything down that could go wrong. It'll be an unpleasant list.

Now, here's the key part -- go away from that list until you're in a better mood.

Just go do something else.

Once you're feeling better, build each one of those statements into two different questions --

Question #1: "What if... [that]... happens?"

Question #2: "How can I prevent... [that]... from happening?"

So if you were worried, "There's no chance I'm going to stick with my weight loss plan through the holidays, it's going to be like very year, I'm going to pig out and go totally off the rails and be wrecked."

Then you'd write,

"What if I go totally off the rails on my diet during the holidays?"

"How can I prevent going totally off the rails on my diet during the holidays?"

This lets you do a few things.

First, you can contingency plan. Contingency planning is hugely underrated, because we live in a culture that has a bias towards positive thinking that borders almost on magical thinking. No-one wants to consider things going wrong, for fear that they'll somehow "cause" the thing to go wrong.

There's some truth in that (you need to think about what you want more than potential problems), but also a lot of nonsense (plenty of issues can be prevented with just a little consciousness of them). When I do consulting or when I'm mentoring someone on the team at GiveGetWin, I always want to look at things going wrong upstream when no negative emotions have set in.

Say a key prospect has agreed to call you on Friday. Decide now, not on Friday, what you'll do if he doesn't call. Contingency planning makes you feel prepared, and makes you act in a sane and organized way when things (inevitably) go off-track.

So when you ask, "What if I go totally off the rails on my diet during the holidays?" you can then contingency-plan. You can say, "I'll put in a check-in call with a fitness oriented friend, and I won't let the negative trend to continue no matter what. Two days after Thanksgiving, I'm going to be back on my clean eating diet no matter what."

You can also ask, "How can I prevent going totally off the rails on my diet during the holidays?"

One of the best Thanksgivings I ever had was volunteering at a soup kitchen instead of just pigging out and watching football. Could you organize an experiment this year where your family all volunteers, donates the cash that would go to a lavish meal, and simultaneously avoid gorging yourself beyond what's healthy?

It's just one option that might come to mind if you start thinking through your options. You could also ask whoever is hosting Thanksgiving if you could fix your own plate instead of having stuff heaped on it, and focusing on large quantities of the green vegetables and skipping the mashed potatoes, and with only a small taste of pie -- thus mitigating at least some of the damage.

When you feel that haunted sensation of pessimism sneaking up on you, embrace it. Write it all down. And then draw up some contingency plans and alternatives. It's a powerful way to place you more firmly in control of your life.

Sebastian Marshall authors The Strategic Review, actionable long-form insights from strategy. You should get a free subscription at http://www.thestrategicreview.net