Go for the combos. The two best combinations are the wrapped candy and the stripped candy, and the sprinkle do nut hole and the stripped candy. Together, they can wipe out over half the board for you. This can also help you get to places which are off the board or otherwise difficult to reach. This is the only way you will get by levels such as 181, which have unreachable squares. Also, a wrapped candy switched with another wrapped candy will ignite a 6 by 4 square which can clear a huge area.
3.
Know your stripe. Candy is stripped in the same direction as the final candy moved to complete the previous formation. If your move a candy horizontally, it will make a horizontal stripe, which will then explode horizontally as well.
4. Assess your threats. Prioritize getting rid of evil candy by their threat levels. For example, I usually make it a rule to kill low number bombs first, then chocolate, then got after the blocks.
5. Clearing jellies on the edge. When getting rid of jellies, only worry about the edges, especially the corners and bottoms. These jellies have the least number of combinations which can eliminate them, so will be the hardest to get rid of. Take a moment each move to see if you can get rid edge jellies and, if not, go after an easier one.
6. Have a plan. Each time you start a new level, look at the hardest element on that level and think out how you can defeat it first before you use up lives. Also, pause between moves. You may have a sprinkle and not even realize it if you're watching the candies from a lesser move get crushed.