This is a project I have been doing for about a month. It is 2.5 ft by 3 ft. It is by far the largest piece I have done yet. It barely fits in my hatchback! Such a large piece brings other practical issues like having a desk large enough, reaching the top of the paper by leaning over it, keeping the cat off of it etc.
I really enjoyed doing the mountain and cacti. The rest is still not fully decided as I have yet to determine the levels of shading.