Harvard Business Review reports that critical thinking skills (think selling skills that are strategic) are what is needed today for sales. One of the first things you can do is to rank your prospects and existing business. (First, determine criteria for A, B and C accounts)
Determine the amounts of time to allocate to your A, B and C accounts. Now use those guidelines to sell and spend more time and resources with your high priority accounts. You can no longer kid yourself (or your sales manager) that a C account is suddenly more important than it is.