1. First of all we'll need to cut the girl out of the background. The cutout doesn't need to be very exact and flawless and you can use some plug-in. I used SmartMask this time. You can find the tutorial on how to select images in Smart mask here, at akvis.com. It's needless to say that the cutout should be on a separate level or in a different file even.
2. Go to Image > Adjustment > Curves and increase the image contrst and brightness with a curve.
3. Duplicate the layer and make the copy invisible for a while. We'll need it later may be.
4. Now go to Filter > Artistic > Poster edges and use settings you see below.
5. To make the colors poster-looking too we go to Image > Adjustment > Posterize.
6. Image > Adjustment > Brightness/Contrast to add brightness.
7. Now we'll use Selective colors to make the colors softer.
Reds
Yellows
Whites
Magentas
8. Make visible the top layer and desturate it by going to Image > Adjustment > Desaturate.
9. Go to Image > Adjustment > Threshhold and use it to leave only detail like eyes and hair visible.
10. Create a new layer underneath the posterised image and fill it with some color. It's good if it is in coordinance with the image colors.
11. Change postersized image layer blending mode to Dissolve (here all the faulty edges of the cutout will be not visible).
12. Return to the top layer and change its blending mode to Color burn.
13. At this point you should employ your fantazy to add more elements to the poster. I used here Sparkle Stars brushes, that you can find at Emma Alvarez site. Some of them are on the same layer as the posterized image, others on the newly created layer at the top. To give the image some depth taken away by posterization I also added a white stripe on a separate layer under the posterized image and twirled it to the maximum.
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