The first thing that you need to consider is your blind spots. You might be very good at your job and if you have been tapped for promotion, this is extremely likely, but the truth of the matter is that these are things that you might not see. Are there areas that you are missing entirely, or do you find that because of intense focus into one area that you miss all others? How much time have you allotted to becoming a well rounded team player, and have you taken the effort to make sure that everyone around you trusts you, if not feels comfortable with you? Remember that as an executive, you are going to need to find ways to grow and to change.
Also remember that you are going to need to consider how well you interact socially with people. Remember that you do not only need to impress the people above you; staying on good terms with the people below you can be just as important. Take a moment to make sure that you can communicate sympathetically with everyone around you and that you understand how much your words might be affecting them. This can be an essential part of getting your work taken care of and of making sure that you are going to get the full cooperation of the world around you. There are so many different options available to you in this respect, and at the end of the day, it is essential.
Finally, keep in mind the fact that as a good executive, you are going to need to ask the hard question; the thing that you might not have realized is that you need to ask them about yourself! There are so many things that you need to consider when you want to do a good job that self-questioning can get left by the wayside, and it is important to remember that this is largely inappropriate. Ask yourself where you are falling short and with an eye towards honesty and even brutality, ask yourself where you have failed or made mistakes. These are hard questions to ask, but at the end of the day, they are extremely important for what you need to do.
Take some time and make sure that you consider what you need to do to make yourself a better executive. Take a look at the company around you and ask how you can learn the most important things about yourself.