Canvanizer focuses on the creativeness; therefore, do not stick yourself with one first idea. Try to sketch different business models by using “Copy Canvas”.
Start with the existing canvas and brand-new ideas will flow without impacting the original canvas. This way you can also "fork canvases", meaning that you keep the state of a canvas before making bigger changes, so you are free to compare them later.
Working with canvases is prototyping, so it is especially important that you iterate quickly and feel free to change. Just create a new canvas after each milestone. After all, they are free :)