Right, I just pull the slack out and take two steps back to ease it free, and look for my spot marker. When I fly in the churchyard across from my house, I obviously don't want to paint an orange circle on their lawn, so I just toss down a white rag to keep me from hitting the stooge on one side and the oak branches on the other side. I move the brick and bungee cord to follow the angle of the TE of whatever plane I'm flying, and anchor it with a guy line into the ground so as not to tip it over. If you have the option, a crosswind helps, but I can even launch most of them with a tailwind if I have to. If your plane is heavy or a little under powered, bungee it to the top of a bar stool and tilt it up. It's very safe and secure, makes cranking and needling easy and has never failed. I fold the mat with the rubber on the inside, and it works best after it gets greasy.
Hope that helps.
Here it is in use: