I'm working on matte painting next, but finding it a bit hard to get the hang of. Having worked out environment concept art the idea is not SO different, though I am having more trouble blending the items and covering up my concept ideas. It's getting there. It'll just take practice.
After I saw a tutorial for this, I went onto twitter and facebook and asked people to give me sci-fi scenes or scenarios that I could practice with. I really wanted to be able to take someone else's idea and make a concept for it. This particular one was a very detailed scene from someone's game world concept, and the idea intrigued me. I thought it would be easiest of the ones I gathered in terms of skills I already have, so I went for it. I might have to set it aside for later, though.