This is the first tutorial I've shared so I hope it works out for everyone. If anyone has any questions I'll do my best to help. I've assumed you'll have some knowledege of photoshop to begin with. This tutorial simply shows the method I used. It was created in Photoshop v.7 but could be easily translated to other programs.
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Ok here we go, I'm going to brightening up a dark screen cap and going from this:
to this:
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1. Select and crop the area you'd like to use, resize to 100X100 pixels. Sharpen the image once.
2. Duplicate that layer twice. Ensure they are both above the base layer and then set their filter modes to screen.
3. Duplicate the base layer again, move it to the top layer. Set the filter mode to soft light and the opacity to 60%. Now your icon should look like this:
If you've done that right, flatten the layers.
4. Duplicate the base and set the filter mode to screen, opacity 60%.
5. Take this texture (sorry no idea where it's from) and set it's filter mode to screen, 50% opacity.
6. Create a new layer, fill it with #B2A693 and set the filter mode to color, opacity 35%.
7. Create a new later, fill it with #B7FFF9 and set the filter mode to color burn.
8. Create a new layer, fill it with #ED5785. Set the filter mode to color burn, opacity 10%.
The next steps make really minor changes to the coloring so there's no need for example pictures.
9. Duplicate the base layer and drag it to the top. Desaturate. Adjust the levels (settings: RGB: 11, 1.13, 223). Set the layer mode to screen, opacity 25%.
10. Create a new layer, fill it with #E2DFCE. Set the filter mode to multiply, opacity 15%.
11. Create a new layer, fill it with #B2AB9E. Set the filter mode to color, opacity 25%.
12. Duplicate the base layer and drag it to the top. Set the filter mode to screen, opacity 20%.
13. Duplicate the base layer and drag it to the top. Set the filter mode to soft light, opacity 20%.
Add some text and you're done. ;)