I used Dupli-Color white auto primer to prime the zombies. I followed that with a brown wash, made up in this case of Reaper Master Series Brown Liner thinned with a 10%-by-volume solution of Future in distilled water.
The Waitress, front and back:
I had been somewhat aware of this as I was assembling the zombies, but it really starts to become apparent when you look at the primed and washed miniatures. These zombies are blobby, and details are very soft. In the case of the Waitress, her left arm blends into her uniform with no demarcation line. Her left eye socket is blank. Turning to the back, you see that the fingers holding the plate are of irregular widths - in some cases, resembling flat noodles - and her left hand (which is cupped) has little to no finger detail at all. The heels of her shoes are irregular. Even after filing, there's a visible seam at the bottom of the plate she is carrying.
Loverboy
The detail on Loverboy is a tad better. Again, the hands are undetailed, and there's a line resembling a crack at the top of the left wrist. His eye sockets are pretty blank, and he's got weird deep lines in his throat, as though he were a really old man even though he's dressed like a teenager. From the back, not so bad.
The Butcher
The Butcher is a relatively nice miniature. You can see that his left foot is broken and dragging. There is some visible damage to the right side of his face, and his right eye is quite protuberant. His left eye socket appears blank. (There is actually an eye in there, but it was obscured by the wash.) Problems: His left hand is lumpy and lacks detail, and his butcher knife is lumpy and malformed. Overall, one of my favorites of the bunch.
The Biker
The Biker has some proportion problems. I think his legs wind up looking too short, although possibly his pants are just hanging low. In addition, his feet are oddly bent off to his left, and I'm not sure what is going on with his neck. From the back, you can see that his left hand has no fingers, and his chain is just a strip of greenstuff with holes poked in it.
The Sheriff
This may be the best overall sculpt in this batch. His bent-in feet are obviously due to a zombie shuffle, and the same with his oddly-positioned gun. I think possibly I should have just bent his right arm up a little bit, as that drooping isn't natural. You can see that his tongue is sticking out of his mouth. From the back, you can see some nice folds and creases in the cloth of his uniform.