The blank canvas is, as the name says, empty. It is a blank slate for you to fill. Either use it to make your own canvas or stick post-its on it and see what happens organically.
The blank canvas can be used in two ways. You can use it to make your own canvas, as described in the step-by-step guide below, or you can use it to let patterns emerge organically, perhaps confronting the team with their own uncertainty. Keep a blank canvas to the side of your workroom and use it to collect the things you are uncertain about, or the ideas you need to work on that don't have a clear purpose at this moment.
The canvas has a lot of white space for you to explore.
Before you begin creating your own canvas, take a little bit of time to think about the purpose of that canvas. Canvases help you structure information (typically using post-its) visually, and it makes sense to think about the questions you would like to see answered, and the patterns you would like to see.
It is too easy to just put a few unrelated blocks together on the page, give them names, and then say you're done and have created a new canvas. Doing that is pretty useless. Good canvaseses follow a few basic guidelines.
Depending on what you want to clarify with your canvas, there are a number of 'perspectives' you can adopt. These are the basic flavors of canvases you already know. A canvas should primarily deal with one of the following perspectives. Choose one as your main perspective.
To make the canvas easier to read, use a metaphor. If it is just a collection of rectangles, the user won't immediately get the picture. The metaphor could be quite abstract, or really shaped as a picture. Generally, if you make the canvas more detailed, it becomes easier for a larger group of people to understand what to do without much instruction.
To draw the canvas, use two steps. It may be quite tempting to just take a marker and draw what you have in mind, but in practice it usually turns out that the organization on the page needs to be changed. So, post-its to the rescue!
First, come up with the different building blocks you need, and write them on post-its. Try to organize these on the page. See if you have everything. Get a feel for your spacing. How are the blocks related? Are things that belong together in the same spot?
Next, test your design (yes, before drawing it!) - come up with one or a few examples and try to fill them in. Does it work? Or do you find that you need an extra building block? Which blocks are really full and need more space? Which ones are quite empty?
Finally, after a few rounds of testing, use the locations of the building-block post-its as a guide to draw your canvas. Remove the post-its, and add a description for each of the building blocks in smaller print.
Now, the time has come to review and test your canvas. Use it a number of times. Keep track of what works, and what doesn't. Do users struggle with some of the points? Do you get the output you were hoping for? If not, go back in and adjust it.