3D Set Extensions by Andrew Kramer is a new tutorial that attempts to transform stock footage into a dark landscape with 3D fog and mountains.
Kramer covers 3D matchmoving inside After Effects using the new Camera Tracker plug-in from The Foundry, as well as Trapcode Particular to create soft clouds. Video Copilot is now selling both plug-ins. Included in the free project download is free footage from Artbeats.
Another part of tutorial is doing sky replacement. For more on that see Sky Replacement with After Effects: A mini-roundup of tutorials here on PVC. Also there’s a bunch more samples and resources for Camera Tracker and Particular on AE Portal archive.