This is one thing that I have been applying more to my design practice. Because we both are delivering ideas to whomever we are doing a project for. Whether its for ourselves or for a client there is a process of delivering ideas. Categorizing ourselves into just the category of being a designer brings up what a person would expect.
Being a designer is the profession behind the creativity. When you know to deliver your creativity in a professional manner then you can either call yourself a designer or an artist. Really that would depend upon you and whether your work solves a problem or whether its just to look pretty.