Word of mouth can help. If you have a good relationship with current clients, ask them if they can recommend any potential new clients.
Contact your local paper and offer to write an article on common errors that cause small business's problems, they are always looking to fill space and you get your contact details in the article. Try and make it interesting so it stands out a little
For serious targets, offer a personalised meeting and have some good powerpoint slides that demonstrate your 'value proposition'. These need to focus on your advantages (price, personal service, accuracy?). Differentiate from your competition - will you give your mobile number out and take calls at weekends?
Don't take no for an answer, the average selling effort needs multiple contacts.
Get involved in organisations that have a lot of targets (Chamber of Commerce, local traders associations?) Don't be too pushy, take your time)
Good luck