Several loose sheets of white cartridge paper at least A3 size or bigger (or a drawing pad that pages can be torn from).
Three A3 size sheets of 140lb/300gsm NOT cold pressed watercolour paper (eg: Langton or Bockingford, which can both be purchased as pads online or from Hobbycraft or other outlets).
As many different media as you can muster, but please include: charcoal, soft pencils or graphite sticks, putty rubber, watercolours, water-pots, brushes, rags or paper-towels.
If you have any oil pastels please bring them too.
Bull clips or masking tape will be extremely useful to fasten your paper to a drawing board.
Finally, please don’t forget your packed lunch!