First, make sure your website is responsive for mobile devices. A responsive site resizes to the device that is viewing the website so it is easy to read on any screen. Also make sure your website is up to date with the latest news, products/services and events.
Do you have an email list of your customers? Start sending a monthly email newsletter using a free email service provider like Mailchimp. Add the monthly article to a blog on your website.
Ask your customers for testimonials and case studies. Write up a case study and put it on your website. Send a pitch to relevant media or trade publications about the case study and how you solved a business' problem.
Set up profiles on social media sites where your customers visit and engage with the community. Search for keywords in your industry and listen for people searching for your type of product/solution. Be helpful, not salesy.
If you don't have time to do these things, hire a marketing contractor. A contractor can help you define a strategy and then set out to make it happen. Contact me today to help you get started.