Being an entrepreneur means having a dream, a grand vision about what must be changed in the world to make it better. When those dreams and goals are huge, the entrepreneur can be called ambitious (in the best sense of the word).

Entrepreneurs make promises. To themselves, to their employees and to the community.

Solving some issue, making life easier, making more money -- these are just a few of the most popular promises made.

But the difference between a dreamer and a successful ambitious entrepreneur is that they work hard to achieve those goals

How to find the strength to actually do all of this, when the euphoria has gone and work in the office turns into a cold routine?

Write it down.

The first thing you need to do is make a written contract with yourself. It doesn't have to be a public blog post telling everyone what you plan to do. It can be a simple piece of paper that states your resolution and why you're committed to it.

Studies have shown that people who write down their goals get significantly more done. This study by Dr. Gail Matthews found that “more than 70 percent of the participants who sent weekly updates to a friend reported successful goal achievement.”

Related: 2 Habits Most Entrepreneurs Don't Develop But Should

Set measurable goals.

One of the main reasons people fail their long-term objectives is not adding measurable short-term goals.

The usual dream has two things in common: it's hard to do and the deadline is far away.

So, naturally, most people postpone it for as long as possible and then fail.

That's why you need to set milestones along the way. Those milestones should be measurable so you can easily and objectively say if you've done them.

A good example here is Mark Zuckerberg's challenge to run 365 miles in 2016.

Instead of saying: "I'll run 365 miles sometimes in 2016" he said “ I'll run one mile a day.” This resolution doesn't allow you to think "I'll start next week."

Related: 8 Ways Successful People Beat Procrastination

It's the same with all big dreams. You need to cut them down to small tasks which you'll do every week or month.

This method is actually a popular management tool called Objectives and Key Results (OKRs).

OKR's are widely used in Google, LinkedIn, Zynga and other big companies to keep employee's goals aligned.

Monitor your progress.

Big goals also need daily time management and planning to stay in focus. If you already have a plan for reaching you dream, you need to make sure you keep fulfilling the plan.

For that, you need to track progress and avoid fake work.

There are a lot of good apps for to-do lists or personal time management. Use some of them.

Apps that track time (like Toggl) make sure you spend your time productively and keep the focus on fulfilling your resolutions.

Related: 5 Terrific Tools That Track Time

Don't be afraid to fail.

A recent study showed that people who previously took part in a “dry January” challenge generally decreased their overall use of alcohol even if they didn't manage to last the month.

So even if the goals set seem to high to achieve, you shouldn't just give up.

The higher the goals, the more you'll push yourself.

Or as author Norman Vincent Peale said: Shoot for the moon. Even if you miss, you'll land among the stars.

Trust yourself.

There are a lot of people out there who say that you're gonna fail.

From friends who jokingly say "you'll never manage to eat healthier" and "come on, you don't have to quit drinking entirely" to co-workers and bosses who think you shouldn't start your own start up.

If that happens you need to look back at the paper you wrote your plans on. Let it remind you why you're doing what you're doing and believe in yourself.

No one but you.

In the end, the only way to achieve great big dreams is to focus on it each day.

The best thing to do is to use every technique possible to hold your focus and keep your eyes on the prize.