If you're looking to position yourself as a leader in your industry you've probably found yourself focusing on the intricacies of the accounting industry itself. While this is a mandatory aspect of what you do as an accounting professional, a way to differentiate yourself from the competition is to be an expert in your client's industry.
Make it a point to subscribe to publications focusing on the industry you find your practice wanting to grow the most, or the ones your practice has developed a strong client base in. Join advisory committees or alliances focused on strengthening that industry. You may not stay ahead of the curve in keeping your client informed of changes in their industry but your ability to discuss these topics will go far to solidify your relationship and differentiate you from the firm down the street.
If the idea of having to read yet one more publication or trying to stay abreast of a whole other industry seems daunting, use your staff. When your staff has down time be sure they know they should be updating themselves on the client issues you need to know about. You can assign different industries to different staff members so they can start learning to be an expert in that area. Not only will you be encouraging your staff's education of a client's industry, you are teaching them the importance of cross-selling services by knowing the client's business needs.