>>1902436I put together a demo image for what I mean about eyes. Being as I'm already using a second partially transparent layer I messed around with altering small things between the two layers to see what result I would get and I liked the way the eyes came out. This particular one combines iris types 1 and 3 in different shades.
The two layer thing admittedly does make things more of a pain for putting together clothes and doing poses (as well as eating available character slots), but you can get some interesting effects that a single layer can't manage.