Hi, First of all do you have a professional looking website that works properly on all smart phones, tablets etc? If so does it come up on the first page of google organic local search results?
If no to any of the above then maybe worth having a chat with Nathaniel Jones the web guy that is advertising on this forum.
As far as yell advertising is concerned who realistically uses phone books anymore or actually uses their online directory these days when the likes of google works so well? The only calls I can guarantee you will defo receive will be from yell sales team trying to extract loads of dosh from you for a paid listing.
Regards to advertising in other ways depends what your target market is and what areas you need to gain extra clients. Say If wanting to target mainly domestic then maybe you could consider advertising in a well established, highly distributed local parish/trade mag. The one you already get posted through your door on a regular basis perhaps. Best to do this over a few months and see how it goes so your name gets known rather than a one off.