Zoom creep is what happens when gravity causes your lens to zoom in or out due to it being pointed up or down. While it’s not really an issue when you’re shooting hand-held, it can cause problems if you’re trying to keep the zoom fixed while the camera’s on a tripod. A trick to combat this is to use rubber bands to keep the zoom ring still, but now there’s a fancier solution to this problem: the Lens Band. It’s a gel bracelet-style band that’s wrapped around the zoom ring when not needed. When you want to freeze the zoom, simply slide half of the band over the lens body.
They’re available in a variety of colors and sizes to fit most lenses, and cost $5 each from the Lens Band website.