Layer Mask and Adjustment Layers
This is the edited photo, I used adjustment layers to change the brightness and contrast while leaving the sky out of the selection of what was affected. This is the original, as you can see the sky is more or less the same. This was edited to add in this turtle and adjustment layers were used to help make it blend in and to improve the photos. This is the original background. This is the photo where the turtle was taken from. Layer masks and adjustment layers were used to combine these two images. This is the original background image featuring my brother and his girlfriend. This is the landscape I used a layer mask to add over my brother and his girlfriend in the edit above.