From there, it becomes a matter of not breaking the chain, not breaking the streak. Mark a red cross on each day, and keep going.
If you haven't marked today yet, today's entry in the above calendar should be a link that allows you to mark today completed.
You can also gain one, two or three credits. Each day you don't draw, you lose a credit. If all credit is gone, you have broken your streak.
Alternatively, there is also a “I’m done!” button. Click on it each day when you finish drawing. And then don't miss a day. Please always use the “I’m done!” button from the same browser, as the streak is recorded inside the browser's local, private storage.