If you want to be a successful freelancer and not tied down to a day job for the rest of your life, you only have to be good at what you do, right?

The biggest name, millionaire freelancers produce the very best work, don't they?

The short answer: no.

There's so much more to being a successful freelancer than being great at your job. Being great is the prerequisite to going freelance, not what makes you successful.

So what is it that makes a freelancer successful? We asked a handful of our favorite (and quite successful) freelancers that very question and here's what they said.

Say no (a lot)

As a freelancer, your gut reaction is to book as much work as possible. You never know when work will dry up and that's a panic-inducing thought.

If a new referral emails you asking to chat, you instinctively drop everything and email them back to set up some time. "I can't turn down business, I can't miss an opportunity," you say to yourself.

But the most successful freelancers I spoke to turn down work--a lot. Their strategy is to either not respond to the email and wait for the client to send a follow up or to respond with a pleasant "I'm full on projects right now." If you're good at what you do, the client will email back pleading with you to fit them into your schedule. "Did you get my original email? I'd really love to talk," they'll ask.

Now you've got the upper hand. Saying "no" is the only way to get leverage in the freelancer-client relationship. Other than that, the client has all of the leverage: they're bringing you business, and in turn, paying you.

By saying no, the client knows that you don't need their business because you're in such high demand. That's a clear sign to them of your value and a great tone to set at the start. They'll want you even more.

Sell your advice as a product

No successful freelancer goes their entire career without having to do a little marketing. Now, this can be as simple as posting on social media and emailing old clients for referrals, but the most successful freelancers take it a step further: they create and distribute content.

Whether you're a writer, nutritionist, designer, developer, etc, there's content that you can create and sell to build your brand. A popular content tool for freelancers is Coach. You can use the Coach platform to distribute your content and then use their scheduling tool for clients to be able to contact and book time with you.

Currently, content is the best form of marketing yourself; it demonstrates to clients that you know what you're talking about AND that people are willing to pay for your expertise.

Talk more than you work

Being a great communicator is as important a part of a freelancer's skillset as any other. You need to be able to clearly and articulately communicate with the client throughout the entire process.

Great communication will help you land the work, but will also help immensely when you go to sell the work to the client. Being able to clearly walk them through the work you've done will put you and your work in a better light. If you find yourself stumbling to explain what you've done, the client may begin to doubt the work.

In short, even great work never speaks for itself.

Be flexible

Anyone who has worked in client services knows that a little bit of patience and flexibility goes a long way. Clients will often come to you with requests that feel as if they came out of nowhere. You can either argue and say no--sometimes that's the best approach--or you can be flexible and work with the client to find a solution.

The most successful freelancers will tell you that you need to be flexible, but not to the point of sacrificing your integrity. You need to set clear expectations with the client upfront, so that you're not being overly flexible to the point of being taken advantage of.

Never budge on your rate

Less successful freelancers will take projects or hourly work at rates below what they typically charge clients. This is bad for both you and the client. You're less inclined to work hard for that client as they're paying you less and, in turn, the client is getting lesser-quality work. This will lead to eventual conflicts and problems.

More successful freelancers will turn that project down by saying no and one of two outcomes will happen: (1) the client will come back and agree to pay your full rate or (2) you'll get back the time and mental energy that you would have spent and use it for finding clients that will pay your rate or use it to build your reputation (by creating content).

Look past your client

When you're working on a project that suddenly becomes a nightmare or with people who you can't wait to get away from, it's easy to take out your frustration on the work and do a lesser job.

But successful freelances know that putting out crappy work will only hurt your portfolio and reputation in the long-run. Our freelancer friends say, "instead of focusing on client frustrations, try focusing on the customers who will be interacting with the work you create."