I want to make my lizzies look like a red cheek turtle:
I like that idea. In general I like the idea of crazy paint schemes. But with the Lizardmen it makes a certain sense because there is such an amazing array of colors in the reptile family.
The problem is balancing the look that you want with the time that you want to spend painting a unit of saurus. I think that the best way to do this in a reasonable amount of time would be to use crackle medium or masking fluid. Vallejo makes both, and you can read very short how-tos on their website, but I don't think I'm supposed to post a link to that here. In the box that says, "select a topic," choose Auxiliary Miniature and Model Colors. Lay down your yellow first, then apply whatever fluid you choose, and then apply the dark color.
The crackle medium will give you a jagged look... or maybe a scaly one? Hmmmm. The best bet might be to take a really small brush and do thin looping line with the liquid mask, and then apply the dark color, I imagine that could give you an effect like the turtle.