I like doing these small thumbnail studies to explore and play with various concepts and idea. It's a quick way to push out ideas in the broad stroke without worrying too much about the little details.
I can always further refine the composition and take it to full matte painting if I want to fully realize a concept. But at this stage, it's really about the ideas and not the details. I try not to spend more than an hour on each, 2 hours is max. Enjoy!
The following are examples of set extension of a jump stage I did recently for a commercial. On the left side are the original plates with the set that the actor interacted with. I had to paint out the areas that were not needed and also build a realistic jump stage to replace the original one. Fun stuff!
Below are some close-up. I like to work at 4k to get into the nitty gritty of the image to paint the little details and then compress it down afterward to hd format for delivery.