I've gone for a semi-block and wash method. Rather than solid blocks of colour, I've started with a white undercoat and used slightly thinned paint so it starts to create a bit of colour variation. Be careful about thinning too much as it will end up looking really chalky or patchy. When applying the washes I also tend not to apply it all over, but apply it to where shading or colour tones need to be.
For example, the black trousers start off dark grey and get a black wash all over, with things like the knees wiped off before it dries. This gives a fairly basic shadow/highlight and generally darkens the whole thing. Then the knees and the bottom parts of the trousers get a secondary wash of brown for staining and makes it look a little more realistic.
The skin is a base coat of VMC Deck Tan mixed with a bit of white as this gives quite a pale, lifeless skin tone to start with. A 50/50 mix of black wash and devlan mud is then carefully painted into the eye sockets, mouth and any dark places like under the hands. Next up thin lines of devlan mud are painted around some of the muscles, between the fingers and where skin meets clothing to provide some shadowy contrasts and remove the general flatness to things. By this point you'll be thinking that it's going to be looking a bit too healthy for a zombie and you'd be correct. This is where some careful application of purple and green washes to the eyes and cheeks start to bring an unhealthy glow back to the show. We can even add some bruising with a few dots of purple, green and black to the skin.
Once the base model is done, it's time to apply the blood. I've seen people splatter blood all over the place, but I like to be in more control, so I'm stippling on some VMA Hull Red first as this is a nice dark, dried on blood colour. As it is intended to be used in an airbrush it's about half way between a wash and normal Vallejo paint consistency, so on dark clothing it stains, but still allows some of the base colour to shine through; which is perfect. Over the top of this we then stipple a slightly smaller amount of Scab Red for some slightly fresher blood. Once you've varnished them (which I stupidly forgot to do last night before basing them on the acrylic), paint a bit of gloss varnish over some of the fresher blood for that extra wet gore feel.