You wouldn’t grab a sad, wrinkly apple, so don’t grab a sad, wrinkly ginger root. Look for a piece that feels firm and heavy for its size. The skin should be smooth and taut, not all shriveled up like it’s been on a diet.
If it’s already soft or mushy in spots, run away. That ginger is past its prime and will taste like regret and sadness. You want that fresh, spicy kick, not a soggy shrug.