Shield platform dropping
 In Super Smash Bros.
The technique is simple to execute in SSB, as there is no sidestepping in that game to mess with the function of pressing the stick downward while shielding.
As the sidestep is introduced in Melee, pressing the control stick too far and too fast results in a sidestep. Since this prevents platform dropping while shielding, the player must press the stick down during a different action than shielding (such as a dash or shield stun) with close enough timing that the sidestep window is closed but the drop window is still open.
In Brawl, while the conflict between sidestepping and dropping persists, there is now a small window where a drop can be made without triggering a sidestep: the player must move the control stick down to 68.75% of its maximum downwards angle in 6 frames without moving it past 70% of said angle in 4 frames.
Shield platform dropping opens a larger possibility of comboing, tech-chasing, edgeguarding, mindgaming, and out-of-shield options. The player can run and pass under the platform, which cannot be done without shielding in Brawl. This technique also allows Yoshi to act out of his unique shield where he can not jump. This technique is not well known, so those who do know it can trick people with it.