Know-How Exchange : Career/Training

I’ve been working in marketing for about 10 years. All my time has been on the client side. I’m looking to improve my skills and was looking for some suggestions.

I’ve identified a few general areas where I would like to improve. The first is with writing. I want to improve my ability to identify proper writing and become a better editor. Also, I would like to improve my sensibility for design. I would like to be able to identify the correct design and why it’s correct. How color works and impacts people as they view it? Finally should I go for an advanced degree to make myself more marketable? I notice some jobs that interest me currently come with the tag -- Masters preferred. My goal is to stay on the client side and move up the marketing corporate ladder. Are good trainings available to improve writing and design skills? I’m not looking for a book, per se, but perhaps other sources that have helped you improve your skills. And finally is a Masters worth it? I think it would look good on a resume but justifying the expense and time seems a little tough. Any thoughts are appreciated.