The accountancy profession has never had a better or wider range of software available. The emergence of cloud services, particularly, means firms can easily pick up and run with great new tools. The next generation of clients will want a different relationship with you, so you'll want to stay ahead of the game.
Communication. OK, none of us can predict the future, but I think we can safely say that new clients are not going to want to fax you. Nor will they want to receive letters from you or have to post things back. Yes, you use email but you should also make Skype central to your communications. Millennials take instant messaging for granted and they find meetings uncomfortable. You might just get them to join a Skype video call though.
Credibility. You probably look at Trip Adviser before booking a hotel and look at seller ratings before buying from someone on Ebay. Your clients of the future do too, so it makes sense to make your firm's credibility public. By providing a way for clients to give unbiased feedback on the work you've done and then making the results available to business owners looking for an accountant, you can get prospects a step closer to contacting you. Take a look at Customersure.
Document Signing. It's in everyone's interests to get the job done quickly when something needs signing. Paper and the post are the enemy of speed. Electronic signatures are now perfectly legal and clients will appreciate the convenience of approving documents virtually. So let them do so, using a service such as Echosign.
The software suggested above will make your life easier and make clients much happier to work with you. If you want the same kind of improvements for your year-end accounts process, then you should take a look at Checkmybooks.