Number 1 is deliberate practice:

Let’s get the most famous one out of the way first: Hard work pays off.

Malcolm Gladwell popularized the theory in Outliers: approximately 10,000 hours of deliberate practice at something can turn you into an expert.

Via Ungifted: Intelligence Redefined:

…the most elite violinists accumulated about the same number of hours of deliberate practice (about 7,410 hours) by the age of 18 as professional middle-aged violinists belonging to international-level orchestras (about 7,336 hours)! By the age of 20, the most accomplished musicians estimated they spent over 10,000 hours in deliberate practice, which is 2,500 and 5,000 hours more than two less accomplished groups of expert musicians or 8,000 hours more than amateur pianists of the same age.

That said, 10,000 hours is an average. And deliberate practice is not just going through the motions.

You’ve spent more than 10,000 hours driving but that doesn’t make you ready for NASCAR or Formula One.

Deliberate practice means getting feedback and always pushing to improve. It’s not flowand it’s not fun.

But it is what molds champions.

More on how you can become an expert here.

Also, balance giving with toughness:

Wharton Professor Adam Grant explained in our interview:

What I find across various industries, and various studies is the Givers are most likely to end up at the bottom. That’s primarily because they end up putting other people first in ways that either burn them out, or will allow them to get taken advantage of and exploited by Takers.

But that’s not the end of the story. If givers resist being martyrs, or have a circle of “matchers” who protect them, they end up on top:

Then I looked at the other end of the spectrum and said if Givers are at the bottom, who’s at the top? Actually, I was really surprised to discover, it’s the Givers again. The people who consistently are looking for ways to help others are over-represented not only at the bottom, but also at the top of most success metrics. 

More on balancing nice with tough here.

As much as I enjoy the 10K hour perspective - I'm also a fan of Tim Ferris' process of taking something apart and figuring out the crux's of it. It's another way to look at the problem (and may cause angst to someone who's 8K hours in...)

Ah, but we don't always have something we can deconstruct. 

Somethings you will have a knack for, and will come easier, while some you could have 10K hours in and be good, but still not the best. IMO

That's true. 10k works where natural talent and inclinations and passions meet hard work and practice.