Pick a weakness that is not a core skill for this position. You can be candid in your answer; recognizing that you really aren't great at something and acknowledging your need to improve. Be sure to have an action plan in place for improving on this weakness.
Perhaps you are watching TED talks to gain skills in a particular area, reading the latest-and-greatest book on the subject, or maybe you are taking a seminar at a nearby community center. We are all human with our own weaknesses, so don't be afraid to share yours!
"I believe I could improve on some technical skills including Excel and PowerPoint. Currently I am at a beginner to intermediate level; however, I would be more comfortable at an advanced level. I have enrolled myself in an evening/weekend workshop for the next six weeks. We will see how stellar my skills are after that course!"
"I tend to work too hard. I am always striving to be and do better that I forget sometimes it is best to embrace the chaos! Despite that, I make a point to have fun with it."
Sales answer example
"This is super cliche, but it's also true. I am not good at delegating to others. When I become submersed in a project, I don't like to give away any of the control. While this can be good, it can also definitely inhibit the outcome of the project and my growth as a team player and individual.
I am currently working on this, as I know it is a deficit."
Retail answer example
"I'd say something I struggle with is my need to please everyone. While this can be an asset in retail, since the customer is always right (even when he or she is not), I feel it may have inhibited some of my career growth. By always pleasing everyone, I don't always stand up for what I should, or put my foot down. I think this can threaten my credibility or level of respect, which is something I certainly don't want.
This is something I am working on currently: I am working to be able to please the customer, my coworkers, and my boss without being seen as a pushover. I think I have really developed this skill as I've been promoted into leadership and managerial positions, and it's something I will continue to improve upon. I just need to remind myself of it and have small pep talks about it. I also just finished reading "Nice Girls Never Get the Corner Office" in order to help shore up these skills and I'm taking her advice and putting it into practice with great results."
Marketing answer example
"Technically speaking, my greatest weakness is my skill level with graphic design softwares like Photoshop, and the like. In the broader sense, I would say my greatest area for improvement as a professional would be not getting caught up in the minutiae of a project and spending too much time on the small stuff while losing sight of the bigger picture."