You need 51 Crests to unlock Ghastly King, that averages out to getting 3 (or the Gold Crests) in each level. Depending on the kingdom they'll be easier / harder to get Gold in, so we adjust the route like so, you'll be getting at least 2 in each kingdom. (If you miss one, you can always make one up somewhere else, this route is just the fastest way to play Any%)

Banana - 2 (Silver) Orange - 4 (Platinum) Watermelon - 3 (Gold) Apple - 2 (Silver) Strawberry - 3 (Gold) Pineapple - 3 (Gold) Lemon - 4 (Platinum) Grape - 2 (Silver) Cherry - 3 (Gold) Peach - 3 (Gold) Melon - 4 (Platinum) Durian - 2 (Silver) Cactus King - 3 (Gold) Pear - 4 (Platinum) Lychee - 4 (Platinum) Chili Pepper - 2 (Silver) Star Fruit - 3 (Gold)