Do you need to work on your voice and speech? There are many techniques from masters of voice work for actors such as Cicely Berry, Kristin Linklater, Patsy Rodenburg, but my favorite is Arthur Lessac. In the video below we do a quick exploration of his basic technique. Give it a watch if you want to find a gem of a way to work on your voice and an accelerated way to master dialects.
Other links: Lessac Institute
Get the book: The Use and Training of the Human Voice