Roll Safe - From the official Nintendo World Store Twitter

The age old strategy
>Blue Shell is comin after your ass
>2nd place isn't too far behind
>Reverse
>Blue Shell becomes 2nd's problem

Online/local however…
>Same three parts of the strategy
>2nd and 3rd are on to your shit and reverse/slowdown so the blue winged nuke can get your ass.

Fun fact: If you throw a Blue Shell while you're in first place, it will immediately turn around and hit you.