Questions about texturing models, draw calls, and unity.

So I modeled some toon-ish objects in blender. Now I am at the texturing part. I was asked to make a texture atlas of some sort, in order to lower the draw calls in the scene to only 1. So all the textures I will be using, bundled together into one huge texture image, being the texture atlas. Then use that image to texture all the models in the scene. What would be required here, and what would be the most efficient time saving way to go about this? Any and all advice would be greatly appreciated.