Double shine

A double shine (or triple shine, and so forth, as it can be used an infinite amount of times) is the repeated use of Reflector by either Fox or Falco in Melee. It is performed by first using Reflector, jump-canceling it, and then interrupting the pre-jump animation with another reflector. It is very hard to perform and is often practiced at slower speeds in Training mode, though it is considered easier to perform with Falco due to his longer jump animation.

FreddyP from GameFAQs says of double shine, "Double, triple, quadruple, and so on shine is just shine, jump, shine, jump, shine, etc.

Same for both Fox and Falco, and can be done forever. The important thing is that the next shine has to be done before Fox/Falco leaves the ground after jumping from the previous shine, which is 4 frames for Fox and 6 for Falco. You need insanely fast reflexes to do them, and very very few people can consistently do even a double shine in a match."