You can create skies and make them pop with a few easy tweaks in GIMP so long as you take your photographs thoughtfully the renowned open-source image editor can help . These tweaks are also a great introduction to some of GIMP’s more advanced features such as layer modes, layers and layer masks.
When taking your photographs, you can do an easier job of creating skies by employing a couple of steps. If your camera supports changing speeds, shoot at a slow ISO speed. This should always be the slowest speed you have for point and shoot cameras. This is less important if you have a digital SLR, nevertheless you should still use slower speeds.
When taking your photos, use a graduated neutral density filter. Since skies are typically much brighter than whatever is below them, a graduated neutral density filter blocks out light in part of your photo which allows you to get a more consistent exposure across your photo. You should consider getting one. But, if you have no way of fitting filters to your camera or lens or you don’t have one, just follow the next step.