Turn any photo into a dot grid artwork with these Photoshop actions. You'll get great results with dots that change size. They get larger in brighter areas and smaller in darker areas. Free download available.
Time to add some details on the face. When it comes to the eye, it's a good habit to always put blue light on it, using hard brush in Linear Light Mode. Whatever the colors around, I always use blue. Don't ask me why, it just works
There are a lot of "skin brush" packs on the Internet, but if you want to make your own and not to care about any credits, you should be able to do it now. It may look like this below, but I'm sure you can do better. When it comes to the options, the ones from leather brush should work here too.
Use your brush to cover all the skin (light green, Linear Light, very small brush). You may not see the difference, but it's a detail that looks great when printed.
The last thing here will be adding texture to... everything. There's certainly some dust in the air, so it can't be smooth. I'll show you the trick that's used by the greatest artists: create a new layer on the top and fill it with some dark color. Then go to Filter > Noise > Add Noise.
The options can change something, but it's all up to your style. Experiment!
Change the layer blending mode to Overlay and lower the Opacity. The grain shouldn't be visible, but it can't be invisible either. You need to feel this moment.