The sleeper is a fundamental yo-yo trick that must be learnt before many other tricks can be done. A sleeper is when the yo-yo is on the end of the string and spinning. It is then returned to the hand by giving the string a tug or doing a bind, depending on how responsive the yo-yo is.
Start with a throw down, but let the yo-yo stay on the end of the string without tugging your hand. To achieve a long sleeper you need to ensure the yo-yo is not tilted to one side and you must throw it hard.