Did you use the game to render those images?
Yup. Usually i build a white illuminated room go in third person (shift+scroll) and position the camera at a angle where most of the player is also illuminated. As you can see with most of my creations the angle is somewhat different everytime.
But recently i have created another way for brighter skins (just like this case).
I added a simple custom block with a simple green texture. Again illuminated but the green screen block is a lightsource on it's own. And just to have a more common viewpoint for my previews i placed some blocks in the green screen room to know where i need to place the player, which direction he should face and where i need to position the camera.
Finally i have to remove whatever background color using Gimp however i think Photoshop could be more effective (but i don't have PS).