I realise I have not put many tests on here over the last few weeks, as I have been concentrating more on my animation, and also I have been doing a lot of background reading.
I have just found a really good tutorial on the Autodesk website that I will definitely be completing over the next few days. It helps because it also included an unrigged head that I can use, as it is difficult finding decent ones for free.
However the bulk of my learning has been from this book 'Stop Staring' where I have been learning about all the background information of where is influenced in the face by the lower eyelids and the shapes I should utilise to make certain visimes etc. I am just getting to the point where the tutorials begin, so again I will have a practical week or so before Christmas using this.
I think that by taking time to read and understand the build up of the face I will be able to create better blendshapes, so combining these two sources should give me great results.