Weaving

From SmashWiki, the Super Smash Bros. wiki

Weaving is a technique found by Austin, TX smasher Hylian that allows Fox players to move while performing shorthopped double lasers.

To perform the technique, the player short hops and taps B, just as with a normal SHL or SHDL. However, immediately after tapping B the first time, the player holds left/right on the control stick, depending on which direction they want to drift as they continue tapping B for the second laser.

With this technique, a technically proficient Fox can "weave" back and forth or quickly approach or retreat while constantly double-lasering, making laser camping and the chip damage notably more effective.