Success is a game of habits. In itself, "success" is a relative term and so its "achievement" is fully dependent upon the habits you put into place that move you step by step toward the "end" you define for yourself.
To be "successful," it becomes a matter of the routine you put into place for yourself.
Whenever you are looking outward, for example, it is very clear the difference between those who create positive daily habits for themselves versus the people who let life's waves dictate their day to day.
Remember: You are the surfer. It's up to you to ride the waves based on where it is you want to go, versus letting them carry you where they will.

1. Successful people plan ahead.

Failure to prepare is the act of preparing to fail.
Those who are successful at what it is they want to do spend a healthy amount of time planning, thinking, strategizing, and preparing in advance. They don't wait until the moment has arrived to contemplate how they'll tackle a situation. Instead, they get as much completed and ready ahead of time so they are more free to embrace the challenges of the moment.
Spend some time each night, and at the end of each week, reflecting on what it is you've accomplished already and what it is you want to "get done" next. Make your list, create your plan of action, and then let that ruminate in your subconscious while you sleep. And the next morning, you will be one step ahead.

2. Successful people do the hard stuff first.

Lazy people have a knack for getting done all the things that are not true priorities. But when it comes to the hard stuff, they suddenly find every reason why they could not complete the task.
That's because hard stuff is, well, "hard." It is a priority for a reason, and that's because it is the thing that's going to move the needle. But often times, what moves the needle lies in the unknown. It requires a risk, or a leap of faith, in some way.
Those who are successful at what they do know this. And instead of shying away from the challenge, they make themselves do these "hard tasks" first--before allowing themselves the luxury of the easy stuff.

3. Successful people say no.

If you want to go your own way, be prepared to piss a lot of people off.
Nobody likes being told no. That's why so many people say yes to things. They don't want to make others feel bad, or they don't want to sever current or potential friendships, or they don't want to be excluded from future possibilities, or they don't want to be looked down upon, etc.
But the truth is, if you want to be successful, you're going to have to say no a lot more than you say yes. Want to go hang out at the bar? Want to post up for the afternoon and watch football? Want to take an extended vacation? None of these things are bad in themselves, but if you still haven't made your dream come true, then realize that every time you say yes to what someone else wants you to do, you are saying no to whatever it is you truly want to do.
It's a judgment call, and one a lot (and I mean a lot) of people struggle with. Successful people are very conscious of how they spend their time.

4. Successful people invest in themselves.

Both in terms of time and money, successful people see life through a lens of investment.
The majority of people don't invest; they spend. They spend the money they earn. They spend their time with people they don't really like, doing things they don't really enjoy. They spend and spend and then wake up one morning wondering why their life is the way it is.
Successful people, on the other hand, invest. They are conscious of how they spend their time and invest it toward their goals. They invest their money in creating additional revenue streams, not owning depreciating assets. They invest in themselves, taking courses, exposing themselves to worthwhile attractions, feeding their interests.
Investing over time is what ultimately creates wealth, both financially and in terms of knowledge.

5. Successful people surround themselves with other successful people.

Your network is your net worth.
The true value of having a network is not access to "things." It's access to habits and thought processes you would otherwise struggle to create on your own.
When you are surrounded by people who embody the same traits you hope to one day have, it speeds up the learning process. You inherently rise to their standard, and push yourself to grow through imitation (which is actually a very good thing). Similarly, if you are surrounded by negative people, lazy people, angry and depressing people, those same traits will rub off on you.
Surround yourself with people who, in some way, are who you want to become yourself.

6. Successful people study their craft.

I blame school for this, honestly.
There are a lot of people in the world who believe that life operates the same way as formal education. They go to college, get their diploma, start working at a big company, and then just assume that over time their years spent there will carry them up the ladder to a nice and comfortable position (just as you rise from freshman to senior).
Unfortunately, there are situations that reward the fundamental metric of time, and people can climb the ladder of "success" by simply staying the course. But the truth is, those are not the ones who end up becoming thought leaders, innovators, industry experts, or even accomplished creators. Because to do that, you have to actively be studying your craft in ways that does not happen by simply clocking in at 9 and clocking out at 5.
Successful people don't separate their job and their "personal life." Their job is their passion, and their passion is their craft. They study their craft relentlessly because it is part of who they are. It is not dependent upon time. It is merely a reflection of their own curiosity.

7. Successful people are accountable for their actions.

Lazy people point the finger at others and make excuses for why things didn't happen. Successful people own up to the weight of their actions and take accountability for their own shortcomings.
This is a habit and a mindset, and one that takes years to cultivate properly. To truly be successful, you have to be extremely self-aware and willing to question the reality you are living. If things are amiss or not going the way you want them to, you cannot point at others and blame them for your unhappiness, dissatisfaction, etc. You have to own up and admit that you created your reality and nobody else.

8. Successful people believe in themselves.

Lazy people want others to believe in them before they believe in themselves.
Successful people, on the other hand, believe in themselves against all odds, often times long before anyone else does. To be successful, this is a must. You cannot expect others to support and believe in something that you yourself cannot even tap into. It has to come from you before it can come from anyone else.
To do this, however, you must take considerable time to understand, know, and nurture yourself. It's tough work, but it's foundational work, and is often what makes the difference between building something that lasts and instead hoping for short-lasting approval.
Believe in yourself. That's where it all starts.