To take this a step further, I like the suggestion to join ArtStation, but you can also practice your concept art skills by picking an existing project and trying to follow their art direction. This can be especially challenging if you pick an art style that you've never done before. But that is the challenge of being a concept artist. To create art in different art styles to suit the project you're on.
When I worked at Harmonix Music Systems, our concept artists would work on a gritty rock and roll game like Rock Band and then they'd switch gears to work on Dance Central with old school hip hop inspirations.
Jason recommends the following next steps:
- Follow your favorite companies and/or concept artists on Instagram.
- View the art challenges on conceptart.org or artstation to see various artists' creative process and feedback.
- Find an "art of.." book relating to your favorite film or game at your local library.
- Draw draw draw draw - every day!