Speaking with my 7 years of extensive experience in pure IT sales, I would say that the primary way to get more business would be to sell yourself properly. Being an IT company, if you are unable to market yourself well, your customers are bound to have doubts upon your ability to market them in return.
Secondly, DONOT just focus on adding value to the business. That's so old school in today's age and being. Instead, keep your focus towards practical demonstrations of how your customers could benefit short and long term if they opt for your service. Show them how you're different from your competitors and you will be sure to win more business.
Thridly, get your existing and past customers to review you on your website/blog/social media pages. Trust me, real reviews sound like real and do wonders when it comes to attracting new business your way.
IT service provision is a vast domain. If you're looking for sale advice in your specific niche, please feel free to call me.