You have no money for trips to the nearest hobby store, so how do you create a convenient water container? How do you come up with a good means to remove excess water from a brush. It is cheap and effectively free; you are reusing something found or purchased.
Take an empty plastic container, such as one that icing for cake comes in, and cut a small open slit in the lid. This gives us an easy to carry water source. It also helps prevent too awful a consequence if it tips over due to wind, children, movement or other reason.