Contact your borough and county councils to ask where you might post details.

If your county council has a culture, heritage and/or arts service, someone should be able to advise you how to get the word out. What about parish coucil bulletin boards? In fact keep an eye out for posting boards every where. Some pubs are very amenable and some are not. Cannot hurt to ask.

Don't stop at private music teachers. Contact school and college music departments. Some very good young muscians out there and they can be a wonderful asset.

Local music shops often display fliers for tuition and workshops. Tune session should not be a problem.