There's a great facebook group I follow called Virtual Plein Air. The idea is you scout around on Google Maps for an inspirational location and paint. You can then post it to the group for feedback (and some self-promotion too of course).
I gave 45 minutes each to these and it was enjoyable. It's one short step to turning this into a piece of concept art to be honest. Add a focal point like a character or building or something and obviously, dote a bit more time and care and attention on it and you're there.
Whilst I think about it though, these are studies, to learn from. That's their sole purpose. I, however, have a horrible tendency to seek praise and approval, to be validated as an artist. So I post it to facebook and wait in earnest.
Inevitably, because I have only 100 or so people following my page (who are mostly family and friends), I base the success of the paintings/studies/illustrations on how much attention it receives. Facebook has a way of warping reality and I wish I could escape it's appeal but I use it as a sort of blog too so...it's tricky.
That's why I've started posting here. The images are better quality, no-one's reading this(!) and so I can be so much more honest here. I think that's the point of a blog right? Maybe I'm getting it after 7, 8 years of posting online?