I don't understand how to get the maximum possible score. Making special candies doesn't seem the best strategy. Sometimes a sequence of matches in a single move seems to yield better results. But I didn't find in the internet any information about how the points works in this case
You get a lot more points when you make progress towards objectives. This includes (but is not limited to) clearing jelly, diffusing bombs, and bringing ingredients to the bottom. Those objectives garner even more points when they're triggered via a chain reaction; the more chains, the more the points are multiplied.