Gotham/GC Images Just ahead of the 30th ESSENCE Festival of Culture, booking a hair appointment in the next few weeks goes hand-in-hand with choosing your next hairstyle. “Festival looks are just that: festive, fun, eccentric,” celebrity hairstylist Tym Wallace tells ESSENCE. “Pearls, scarfs, tensile, hardware tools (bolts, screws), colored hair sprays, and glitters are always…