Have you talked to any of them in person? At least where I work fitting in personality-wise is almost as important as your skills matching what we need. We spend a lot of long hours working together and things just go faster when everyone gets along, it’s also easier (and more fun sometimes) to critique designs from someone you get along with/know well because you won’t be as worried about offending them.
Have you ever sent them any computer models/renderings? Different companies use a different mix of hand sketches and computer models in their design process, but it’s always a good idea to show that you can illustrate an idea in a variety of mediums.