The first 2 sketches are more of an "automatic" style drawing. There are many ways to go about producing a drawing or sketch but automatic drawing can sometimes be the most rewarding.
You cant really determine if you are going to produce anything worthwhile and its exciting when you do. This process can also reveal things about your self that would be a lot harder to express if you were trying to control the out come of your work.
If you've seen my other posts, what kind of subject matter do you like most?