Painting Theme for a rally?

Hi everyone - one of our committee members and I have been discussing painting, on Facebook, and he suggested having a painting/drawing themed rally.  This is distinct from our bi annual competititions rally, which does include an art section.  What we were thinking about was a rally where we find an expert to lead us, and at the end of the weekend, he/she would judge our work.  So I am wondering if any centre has run a rally like this, so I can pick your brains, and also if we have any semi-pro artists out there on Club Together who would like to be the expert.

Val