In a previous installment, SSBM Tutorials dealt with the options Yoshi has by using his shield parry. However, with such a unique shield as Yoshi’s in Super Smash Bros. Melee — giving him an egg to shield himself, rather than the usual orb — there has to be more to it.
In this video, SSBM Tutorials goes over nearly everything about Yoshi’s shield. They discuss some of the positives — including his ability to store power shields — and negatives, such as the possibility to get punished out of his roll.
Source: SSBM Tutorials