So you have rushed out to shoot a landscape on a sunny day, and while you tried to remember the sunny f/16 rule, you forgot to take your gradient filter with you and you have some washed out skies in your shots. Fear not! All is not lost. Here is a quick and dirty way to fake a gradient filter in Photoshop.
Open your image in Photoshop.
Create a new layer.
Hit “G” to bring up the gradient bar.
In the gradient editor, select “white/black”
Draw the gradient.
In the layer properties window, select “Overlay”
In the Layer properties window, adjust the opacity to suit your tastes.
Well, that’s about it. It’s quick. It’s nasty. And it can save your washed out skies when you’re in a bind.