Start with your base, sharpen and blur, whatever you do to prepare a base.
Duplicate your base, set the duplicate to overlay and desaturate.
Set this by
77words to color at 100%.
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Set this to lighten at 100%. You can move it around to wherever it suits you, I moved mine to the left a bit over her hair.
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Set this one by
ewanism to lighten 100% as well. It looks like nothing has happened, but it makes the skirt a little lighter. You can skip this if you want.
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This by
ewanism to lighten 100% too. Also looks like it's done nothing, but makes the bottom corner of the skirt more pink. Again, you can skip this step if you want.
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Set this, by
ewanism to screen at 100%.
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And that's it.