from this & this
* does NOT include coloring
1 - open a new document, 100x100 px
2 - select two different pictures you want to use, open them up in photoshop. it is better to use up close up pictures rather than ones that don't really focus on the face.
i am using
3 - for the first picture, size it width = 100, length = 50 then do the same with the second picture you've chosen.
both pictures now look like this:
4 - after done with those two pictures, copy them and paste them onto your original 100x100 canvas, put one picture for the top half and the other at the bottom half.
5 - flatten the image, and now you can edit it anyway you want!
(for mine, i changed the coloring.)
comments are preferred here.