This was my set up for my assignment to illustrate paleontology tools, I used my sons toys and fossils. I watercolored the ammonite and then drew the other items in graphite. Once that was done I took them into Illustrator to do some refinements and composition. Then into Photoshop to add the textural components.
Side Note:
My instructors hated the illustration above and told me to redo the Tools Illustration assignment. That redo is pictured below and I got a good grade on it.