Mainly focus on matching candies on 1 side of the playing field. With every Cupcake you destroy it will become slightly easier to match candies. Eventually you’ll want to connect the left and right side of the playing field by clearing one (or more) of the Cupcakes highlighted in red (image below). When both sides are connected it’ll become much easier to match candies and create special candies.
When you get the opportunity create Fish candies because they will go straight for Bottles and pop them. The Fish candies will take care of the Bottles, you need to take care of the Cupcakes.
Start by matching candies as low on the playing field as possible and when the soda level nears the top of the playing field match candies as high on the playing field as possible. Doing this will shift the largest amount of candies, hopefully matching some automatically and create new opportunities to create special candies.
Take your time and pause after every move to check whether you can create special candies.