Have you tried moving your camera when you take a photo of the sky? When the sun is rising or setting people generally take photos of the landscape in the direction of the setting sun. Much more dramatic than the other direction. But include too much sky and the light entering the camera can be too much causing over exposure. Include more land and less sky and the sunset colours emerge more clearly.

By including more land the cameras automatic exposure changes. The area in silhouette may even reveal more detail than if you aim more at the sky. Also remember, if you have a crop tool on your camera you can remove part of the landscape while leaving the sky.

The only difference in these two photos is that I moved between the first and the second and I included more land in the second one.