Maybe it's time to set aside all those “know yourself” advice books, and try lying to yourself about who you are. You are a finance wiz. You are a sales guru. You are a genius writer.
Any successful careerist needs to be these things. But most of us are not really all of these things. The skills are too diverse even for the mind of an overachiever like you. But why not try telling yourself you are all these things and see what happens? After all, the first step to being great at something is to believe that you're great at it. Then you will attack the task at hand expecting yourself to succeed.
Sales
You can say you don't like selling. You can say you're above it. But you may never get the chance to know, because people who can't sell themselves can't get jobs. So, okay, you don't have to sell cars (though you should study the people who do — the best are incredible sales people and could sell anything to anyone.) But you do have to sell yourself to get a job, and you have to sell your ideas in order to keep your job interesting. (Singles, take note: Dating is, in fact, the most important sales game of your life.)
The hardest thing about sales is taking the time to understand what the person you're selling to cares about, and under which scenario that person is a good listener. People who say, “I'm bad at sales,” are people who, for the most part, refuse to take the time to understand people. How embarrassing. So even if you are bad at understanding people, don't announce it to the world by saying you can't sell. Call yourself a salesperson and practice all the time.
Finance
I first learned the importance of faking it when I had to present financials to my angel investors. I had to pretend that I did not score in the bottom 20% of the math section of the GRE. I had to say confidently, “Oh, I have everything explained in an Excel spreadsheet.” And then I had to hire someone to teach me to use Excel.
Today, I don't run numbers as fast as a real finance wiz, but I have confidence because I told my investors I knew what I was doing thereby forcing myself to learn. Thank goodness, because each of us needs to be a finance wiz.
You need to understand broad corporate financial goals in order to place your own projects in context. You need to understand how to manage a dynamic budget without tripping on the question, “How did you get to the number on line six?” Most CEOs did not move up the ladder via financial positions, but you never hear a CEO say he's bad at finance. In an ambitious career there is no room for financial weaknesses. So don't ever say you don't do numbers.
Writing
Here's a scenario: you write an e-mail that consists one, 25-line paragraph with no breaks. No one reads it. At best it looks unintelligible because it's too long a paragraph for email. At worst, it *is* unintelligible. But still, in this case you are a writer, you are just a terrible writer.
The list of scary scenarios is endless: If you send a disorganized report to your boss, she won't understand it; If you have typos in your resume you'll lose interviews. Everyone's career is dependent on their talent for communication. And in the age of email everyone's a writer.
So take responsibility for your own communications and function like you are a top-tier writer. This means outlining first so that you are organized, writing to the point, and proofreading. A few of you will need to take a grammar class. Some of you, who have made some of my past projects miserable, will need to take ten grammar classes.
So lie to yourself. Tell yourself you are great at sales, writing and finance, and you might not be great, but you will get a lot better. And even a small improvement in each of these skills will add up to a large improvement in your career trajectory.