It has become pretty essential in recent years that parties explore and exhaust alternatives to litigation before issuing proceedings.
Mediation has therefore become commonplace. Two things of note:
1. the courts have a small claims mediation service they will invite you to use after you have issued; or
2. you can ask for a one month stay in order to try and resolve things through your own mediation or other alternative dispute resolution.
So you do not necessarily have to done it before issuing proceedings.
Here is an example of a mediation service that I used recently and was not too expensive and reasonable quality:
Centre for Effective Dispute Resolution: https://www.cedr.com
6 March 2018