How can I improve my sales career ?

Do what successful people do.  Follow the leaders, not the followers. Do what the top salespeople in your company do. Imitate the ones who are going somewhere with their lives. Identify the very best salespeople in my field and pattern myself after them.

I want to become one of the best salespeople in my company, I always go to the top earners and ask them for advice. Ask them what I should do to improve my sales career. Inquire about their attitudes, philosophies, and approaches to their work and their customers

you must know all information about your products and all in formation about other company's products

that first thing you must do if you want to improve your sales skill