Most effective way to DI

[Formaldehyde]

I've been playing Smash for Wii U/3DS since they came out, and only recently I've decided to learn how to do more of the advanced techniques. How and ever the one that so far alludes me is DIing, I'm just never sure when it's appropriate to use it, and if it's better to mash the direction repeatably or just hold the direction I want to DI in, would anyone be able to help me out?

 

[Locuan]

For questions like these please utilize the Gameplay Advice and General Discussion Thread:
http://smashboards.com/threads/game-play-advice-and-general-discussion.382927/

Additionally, I answered questions regarding DI in another thread which might help you out:
http://smashboards.com/threads/having-trouble-undestanding-di.398121/#post-18932386