Tips-ups are a great way to have an extra line in the water when ice fishing. They come in many shapes and sizes but their main functionality remains the same. Most people use a treble hook or two with a minnow attached to the end of the line. When a fish latches on, a bite indicator (usually a flag) goes off to alert you of the fish. Then you carefully get a hold of the line, set the hook, and bring the fish up through the hole.