I start with a sketch then add water color, usually a wash on dry paper. I am often doing this outside of the house and the only water is what I am able to carry with me. Usually only a few ounces. This is where wc pencils and a water brush is handy. I often draw while out and when I am back home I use my regular set of watercolors and brushes.
Food and whatever I have to look at in front of me on the ferry to and from the mainland are frequent subjects.