There's no class, Suzie. I think it's more of what you prefer to look at while you are using what you chose for arrangement plants and what you chose as container to use. I have seen many interesting arrangements that are comprised of plants I don't care for in containers I wouldn't think to buy. It's really a personal thing about what things we see as beautiful and what we want to surround ourselves with.
My struggle and goal is to learn stuff that works to make planting easier, plants staying healthy, arrangements longer lasting, finished product aesthetic to my senses, affordable to my budget and worth my time to make it.