I'm working on a model of an iguana, eventually to be fully modeled and textured out to the nth degree.
Perhaps a little mundane, but a pretty good challenge nonetheless. I started out by stalking Flickr for good reference, and found a few dozen great photos of iguanas.
All material except for the reference images is copyright Ed Whetstone 2009. Just in case.
I usually start my creature/character models at the eyes. I think if you can get the eyes to look right, a lot can be forgiven in other areas. It's like macro photography -- You can have extreme, blown-out depth of field on the rest of your image, but if your subject's eyes are in focus, it doesn't matter.
It's always tricky to figure out exactly how big to make the eyeball. They're usually a lot bigger than people would expect just from what's exposed. Getting this starting shape the right size can mean a lot to the model's proportions later on. From here, I worked my way outward, following the contours of the reference image wherever they seemed obvious.
This model will eventually end up in Mudbox, so it's a tricky dance to figure out exactly how much I need to model as opposed to sculpting later on. I'm planning on adding a LOT of fine detail for the final image, so I opted to add as much definition in the base mesh as possible. From here, it's just marching down the head, working my way to the crazy waddle-thing. I'm sure there's a scientific term, but I don't know it.
This is as far as I've gotten, I'll post more as I finish it. All comments and critiques are welcome!