Take advantage of yourself as your own subject. Experiment in both natural lighting in the day time, and artificial light source’s in the night time, and obviously strobes, speedlites, etc (check out the strobist website for lot’s of technique information).
I personally love to play with flash, continuous lighting, and natural lighting. There’s so many endless possibilities. For me; playing with shadows, form and surrealism inspires me enough to continue with my love for photography, self portraits help in my inspiration; I can’t explain why exactly.. I guess they just do.
Night portraits suite my personality well, and I tend to produce weird and wonderful things ( in my opinion). This is a night portrait I did the other night, it’s nothing special I guess:

Hope I helped,
–
Ryan Bater