Imagine you're up for parole. You've been a model prisoner. You've shown remorse. You've even prepared a speech for the parole board to equal Red's from Shawshank Redemption.

Unfortunately, none of your effort might matter.

Researchers analyzed more than 1,000 parole decisions and found that prisoners who appeared before a parole board first thing in the morning had their parole granted about 70 percent of the time.

But as the day went on, the rate of favorable rulings fell to almost zero. (Although it did spike back up for the first case or two after lunch.)

Yep: When you go before the parole board -- the luck of the scheduling draw -- makes a bigger difference than any other factor.

Why? The judges got tired: They fell prey to decision fatigue.

Which is why the best time to make difficult decisions -- to do important things -- is early in the day.

That's what Amazon founder Jeff Bezos does. According to Bezos:

I like to do my high-IQ meetings before lunch. Anything that's going to be really mentally challenging: That's a 10 o'clock meeting. Because by 5 p.m., I'm like, "I can't think about that today. Let's try this again tomorrow at 10." As a senior executive ... you get paid to make a small number of high-quality decisions. Your job is not to make thousands of decisions every day. Is that really worth it if the quality of these decisions might be lower because you're tired, or grouchy, or any number of things?

In fact, Bezos feels it's "enough" if he can make three good decisions each day.

The same is true for you: While you probably make dozens of decisions every day, only a few truly matter. (What Bezos might call "Type 1," meaning "almost impossible to reverse" decisions.)

So how can you make sure you -- and your team -- are operating at your peak when you need to make important decisions?

1. Limit the number of small decisions you need to make.

Every choice -- no matter how small -- you make throughout the day decreases your supply of mental energy and increases decision fatigue.

And then one of two things happens:

You make impulsive decisions: The "Oh, the heck with it" response. You avoid making decisions: The "I can't deal with this now" response. (That's what happened to the judges in the parole board study; as they grew mentally tired, it became easier and easier to delay releasing a prisoner.)

Either way, no matter how much willpower you try to summon, decision fatigue makes you look for shortcuts.

That's why the fewer decisions you need to make, the smarter the decisions you can then make when you do need to make a decision.

How can you reduce the number of decisions you need to make? Add a little choice architecture to your surroundings. Automate certain decisions. Make one decision instead of many by granting authority: Decide who will decide. (And make sure it's not you, unless it really, really needs to be.)

2. Do "high IQ" things early in the day.

The best time to make tough decisions is early in the day. The best time to do the most important things you need to do is early in the day.

Decide the night before what those things are, and plan to tackle them first thing.

And if you can't get them all done in the first couple of hours, schedule one right after lunch.

Although the judges studied started the morning strong, their decision-making graph looked like a roller coaster: Immediately after lunch, their likelihood of making favorable rulings spiked upward.

That's because glucose is a key source of mental energy. Your brain doesn't stop working when glucose levels are low; it does respond more strongly to immediate reward and pay less attention to long-term outcomes.

3. Get enough sleep.

Seriously.

While saying they work 18-hour days seems like a badge of honor for many entrepreneurs, it's also a pathway to disaster. A chronic lack of sleep decreases daily functioning and adversely affects health and longevity.

One study even found that reduced sleep time carries a greater mortality risk than smoking, high blood pressure, and heart disease.

To make matters worse, chronic sleep problems may be linked to a greater risk of Alzheimer's.

On the flip side, Bezos says when he gets enough sleep, "I think better, I have more energy, my mood is better."