Since there are so many posts in here that are neither tips nor tricks, I thought I'd get the ball rolling!
Here's a tip that I use in my listings:
Go to an arts/crafts/diy store and buy the biggest canvas that you can find. Put it on the wall, at a level that a normal human being can reach. Next to the canvas put a jar of permanent markers (we call them "sharpies"). Kick off the canvas by faking the first 'signature" as nobody will draw on the canvas unless they see that someone has already started it. My husband always writes "Thanks for the great visit, Isabelle and Henry, Quebec City". I don't know how he chose that 🙂
Once the canvas gets full, hang it as art and start a new one. I currently have over 30 full canvases after six years of hosting. It will be a cool art project one day, maybe even something hosts in every city can exhibit at the same time!