Don't try this at home: Randall Whitehead, IALD, explains what you must know about lighting design before doing it on your own.
As a professional lighting designer, what do you think I need to learn about lighting before I do it on my own?
You need to become familiar and comfortable with new alternative light sources and light fixtures so that you can make educated decisions on how they would best work for your projects. It definitely helps to learn about color temperature (Kelvin) as well. It is the color of the light that affects everything. You can't look at fabric samples, tile and paint colors just under a daylight situation. You have to look at these materials under the color of light that they will be seen in after the sun has set. The perception of these colors can be greatly altered by the Kelvin rating of the light. I have to warn you, though, there a lot of lighting designers out there already. Have you considered the field of medical or dental assistant? DeVry is now accepting applications.