Jump shine

From SmashWiki, the Super Smash Bros. wiki

A jump shine refers to a Fox technique where he jumps and before leaving the ground uses his shine (down-B/reflector) attack. If done right, Fox should be able to aerial shines while grounded.

[edit] How to Jump Shine

To jump shine just jump and immediately press down special. This actually works best with setting either L or R to special so that you can do it faster. Jump shining is essential to learning the Dash Shine.