For labels and stickers at work, I use a heat gun, but you probably have to be careful there. You could also use a hair dryer and get it warm and then pull it off. I know I'm probably going to get flack for this, but I have always used Lacquer thinner for cleaning every surface of glue or grease. If you wipe it with a clean dry rag really fast right after you can avoid any permanent damage to whatever surface your trying to clean. Works great for getting off paint rubs on your vehicles from parking lot door bangs.