Video: How to replace the sky in Photoshop
If you've ever found yourself shooting in a situation where every element except the sky lines up for your shot (and who hasn't), this handy video from Jesus Ramirez of the Photoshop Training Channel might be just what you're after. In it, he shows you everything you need to know about one of the most useful tricks in the photographer's editing arsenal - how to replace the sky in Photoshop.
Even if your technique for sky replacements has generally just involved simple masking, this video will still have something for you, as Ramirez also covers matching colour and matching perspective, two important aspects that will help guarantee a more convincing replacement.
You can see more of the Photoshop Training Channel's excellent videos on YouTube.