MADE WITH PHOTOSHOP 7.0, but most likely translatable!
From
to
step 1.
Take a base. In this case I took this one:
step 2.
Go to Image>Adjustments>Brightness/Contrast and set them
Brightness: 0
Contrast: 30
result:
step 3.
Add a new layer. Add this gradient (by me,
superbeicons)
and set it to Exclusion, opacity 100%.
result:
step 4:
Duplicate the base and drag it on top. Set it to Soft light, opacity 100% (and duplicate if it's too dark). Merge layers.
result:
Now, if you want to emphasize some object with a (slight) color do following:
step 5:
Add one layer again and choose the Soft round brush 21px, pick any bright color (in this case #FF2B6C) and color over the object. I colored over the cloud. Now set the colored layer in Soft light or Screen, which ever looks better, and opacity 100%.
result:
Then I added some tiny text and a 1px stroke and we're done!