One option that was popular when Essence of the Wild was in Standard was to use it as a 6-drop in Birthing Pod decks. It makes all of your little utility creatures into big beaters, and short of a board-wipe it could be game over. To be honest, this wasn’t a popular strategy, but there are those that did it.
The better option that I had once considered was to play Essence of the Wild in a token based deck, like with Hero of Bladehold and any other cards that create lots of tokens. It would’ve been especially fun with Garruk, Primal Hunter and Garruk Relentless, whose tokens now become 6/6. Needless to say, having 6/6 beaters is pretty fun.
The main issue is this Essence of the Wild’s 6-drop cost, with a triple Green requirement. In Standard, this heavy leaning towards Green proved to be a bit awkward. In any case, Essence of the Wild is especially fun in Commander, with all of the token creation available in the format. This was never the mythic rare you wanted to pull out of Innistrad (why couldn’t you be a Liliana of the Veil!?) but it’s still a good card to try and include in a fun Commander strategy.
I’d still love to see a Modern ramp deck run Essence of the Wild. Now that would be fascinating. I'm not sure it would ever happen, but this is a powerful mythic rare on paper.