What do you do to improve critical thinking?

After watching a nurse demonstrate a clinical skill, I envision the steps in my mind. In addition, I try to find out the rationale for many of the practises that occur in clinical. You?
I think "why" a lot in my head. Why is this happening? Why am I giving this med? Why am I performing this intervention? Etc. I also ask lots of questions. I am finding that critically thinking through situations gets easier with experience and utilizing the knowledge you acquire from the more seasoned staff around you.