Because the Chocolate Spawner is right in the center of the playing field it’ll make it much more difficult to make special candies. This gets even worse when it spreads Chocolate even a little bit. So focus on clearing the Chocolate as quickly as you can and prevent it from spreading too much.
With candies of six colors on the playing field (and the Chocolate Spawner’s location) it’s not only difficult to make special candies, it’s also difficult to collect yellow and green candies. Take your time and don’t miss out on opportunities to make special candies. Make as many special candies as you can and when possible combine them to maximize their effects.
Match candies near the bottom of the playing field as often as you can. Doing this will shift the largest amount of candies, hopefully start a chain reaction that’ll collect yellow or green candies and create new opportunities to make special candies.