Dealing with over-saturated pictures
From this to 
Translatable
Beginner/intermediate
1. Crop your base, but don't sharpen!
2. Right now, this picture is too saturated, and lacking contrast. Duplicate your base twice. Set the middle one to screen and the top one to soft light. Desaturate both layers. Doesn't that look much better? It's not even close to finished yet, though!
3. The image at this moment is blurry, but sharpening it just makes it look even worse! To remedy this, use Gaussian Blur with a radius of 1-2 on the top two layers, then sharpen the bottom layer. This way, the image is sharpened, but not overly so. If you need to, you can go into the base and smooth the skin.
4. To make the whites blend in more, make a new layer, set it to exclusion, and fill with 080C35.
5. The image looks sort of washed out now. To fix this, make a new layer set to color burn and fill it with C1C4EA.
6. Still kind of bland though, right? Make a layer set to soft light, fill with 8A5A40, and the colors will get a lot richer!
7. Now it's too brown! So make another color burn layer and fill with 6DCFF6.
8. Make sure all the opacities are working, do some final tweaking, then merge all layers.
9. Duplicate this layer and sharpen the duplicate. This way, if it's too sharp, you can lower the opacity. Lower it to the right level; I've found that 50% usually works. Use the blur tool set to 20% strength on a small size to blur any over-sharpened skin.
10. Add any textures, brushes, or text you want, merge layers, and you're done!
Translatable
Beginner/intermediate
1. Crop your base, but don't sharpen!
2. Right now, this picture is too saturated, and lacking contrast. Duplicate your base twice. Set the middle one to screen and the top one to soft light. Desaturate both layers. Doesn't that look much better? It's not even close to finished yet, though!
3. The image at this moment is blurry, but sharpening it just makes it look even worse! To remedy this, use Gaussian Blur with a radius of 1-2 on the top two layers, then sharpen the bottom layer. This way, the image is sharpened, but not overly so. If you need to, you can go into the base and smooth the skin.
4. To make the whites blend in more, make a new layer, set it to exclusion, and fill with 080C35.
5. The image looks sort of washed out now. To fix this, make a new layer set to color burn and fill it with C1C4EA.
6. Still kind of bland though, right? Make a layer set to soft light, fill with 8A5A40, and the colors will get a lot richer!
7. Now it's too brown! So make another color burn layer and fill with 6DCFF6.
8. Make sure all the opacities are working, do some final tweaking, then merge all layers.
9. Duplicate this layer and sharpen the duplicate. This way, if it's too sharp, you can lower the opacity. Lower it to the right level; I've found that 50% usually works. Use the blur tool set to 20% strength on a small size to blur any over-sharpened skin.
10. Add any textures, brushes, or text you want, merge layers, and you're done!