Like on this poster:
I personally like it very much so I´ve tried to find some tutorial about how to achieve this effect. I´ve found two which are really great.
1. How to Turn Humdrum Photos into a Cinematic Portraits
This is a really great tutorial describing the whole process of making that amazing lights and shadows.
I especially like one step described in the tutorial - to increase contrast of the portrait add Gradient Mask on the top of the layers, change the Blending Mode on Soft Light and lower the opacity on 75%. The result is really amazing! You should try it.
2. Dragan Effect Photoshop Tutorial
This video tutorial describe quite similar techniques but adds also some more. You can get really dramatic portraits following this tutorial.I especially like one step described in the tutorial - to increase contrast of the portrait add Gradient Mask on the top of the layers, change the Blending Mode on Soft Light and lower the opacity on 75%. The result is really amazing! You should try it.
2. Dragan Effect Photoshop Tutorial
I have only one problem with this tut - author merge all layers after every step. Please, if you will follow this tutorial, don´t do this! If you do, you won´t be able to edit those layers lately if you e.g. realize that you make some mistake or want something change.