Bianca took us through two sketching using Gouache which is a new medium to me.  I wasn't thrilled with the colors in my limited Gouache set so I was using different hues than Bianca was, but I think I understand how the opaque coverage can be more forgiving than watercolors.  I was a bit surprised at how much paint gets used and how it is difficult to rejuvenate dried paint on the pallete but hopefully I'll get better with practice.