Direct Marketing - best way to go about it?

I'm hoping to start acquiring some new clients under my limited company accountancy practice. Due to issues with ACCA being lame with practising certificate requirements (having moved to a job regulated by HMRC instead of ACCA they seem to want to do everything possible to deny me what I deserve after 3 years of hard work) I'm pretty much solely doing Quickbooks Pro Advisor work, book-keeping and VAT returns and maybe some tax advice. Other requirements can be outsourced easily. 

Marketing is not my strong suit though, and I need a cheap way to get my name out there. I have a basic website but it's not going to really get seen by anyone just randomly searching unless they find me on LinkedIn. I can make business cards easily, but my main issue is finding a way to do direct marketing. I know you can obtain listings from Companies House and use direct mailing services like Thomson Local etc, but they seem very expensive and I've no guarantee whether I'll earn any money back. 

Does anyone have any tips or tried and tested methods?