Slicing with or without Peeling: If you want the extra impact of having slightly larger slices of fresh ginger root in your jumbo prawn recipes, you can simply slice your piece of ginger root across the grain (the linear stringy fibers running the length of the root segment). Slice thicker if you want more impact of the ginger as an element in your recipe all by itself. Slice thinner to any level of thinness to vary the cooking time and the flavor impact of the ginger slices themselves.
If you are using ginger root slices in your recipe and keeping them intact as slices but slicing them very very thin, you don't usually need to peel the ginger root at all. Similarly, if you are using a bit thicker slices, you can avoid peeling them and smash them perpendicular to the grain to get the juice flowing a bit and tenderize them a bit - but leave them skin on and as slices.
Fresh Ginger Root - Peeled
Because the fresh ginger root skin is effectively a dried out bit of the interior root, you can't use the fresh garlic clove smash and peel method for peeling the ginger root. If you want to peel the ginger root, just gently slice off the skin from the root segment you are going to use in your recipe. If our ginger has a thicker of more fibrous skin, we usually peel it. We also like our ginger minced up with our fermented black beans and fresh garlic, so we prepare it for that presentation.