Throughout the level you have to focus on the locations highlighted in red in the image below because the Icing and Jellies at those locations are difficult to clear. You can only hit the Icing and Jellies at those locations with special candies.
The first thing you have to do is clear the Icing highlighted in red. Doing so will allow candies to fall through to the bottom of the playing field and make it easier to make special candies.
With candies of four colors on the playing field you shouldn’t have too many problems making special candies. Consider holding on to special candies until you can combine them because of the combination’s enhanced effect.
After you’ve cleared the red Icing match candies near the bottom of the playing field (or as low as possible) as often as you can. Doing this will shift the largest amount of candies. This in turn will hopefully start a chain reaction that will create new opportunities to make special candies.