I set the task for my students today to draw a conceptual sketch of the their project. Not a rendering, not presentation drawing but the first flash that they have of the image of the space. Here are some examples. Two are by the great american designer Ray Eames and two are by ME! I like to do a perspective drawing EARLY in the project to draw out all my preconceived notions. I do not draw a perfect perspective but a very loose idea of the room. It always showed the client that I did have an image in mind and there was no need for any more magazine pictures yet let the project stay loose and continued the creative process.