The game has recently been reduced to such a simple game mechanism that I have found that just by following a few simple rules it is possible to get the best out of any board including legendary levels.
The opening board will give you some idea of whether you will pass or fail. To improve your chances of a pass on your first attempt play starting colour bomb and wrap/stripe. You will also have at least one win streak booster on your first attempt. So the level will always give you your best chance of passing on your first attempt.
Subsequent attempts will be harder. Do NOT waste starting boosters on subsequent attempts. If you fail on your first attempt often the only way to pass legendary levels is to wait until the game gives you enough extra moves for 10 gold bars, and then use 10 gold to pass.
Whether a legendary level can be passed using any strategy is written into the design of the starting board. Do not waste boosters on an impossible to pass board! Nearly all legendary opening boards are "fail" boards. Some will be "lucky" boards. It's important to spot a lucky board and take full advantage of it, but not waste boosters on a lost cause.
If you have a "fail" board then I have found that whatever strategy I use I fail.
If I have a "lucky" board then I find that the following strategy will help me pass.
- Make the first move the game suggests or strike a double colour bomb combo
- Make any move you see that will create a wrapped or striped candy or a colour bomb
- Make any wrap/stripe combo or colour bomb/stripe or colour bomb/wrap combo you see and check the board for chances to create combos of special candies
- If there is no chance of the above make the move that best opens the board and removes blockers
- If there is no good move make the move the game suggests
When you have about 5-7 moves left to play check the board carefully to assess if there is a chance you may pass. At this point the game may stop helping you but there may still be a way to pass either by using a single booster or by making the correct moves. So near the end of a level, if the game has allowed you to get close, it is important to stop and think what needs to be done, and then to make the right moves. This will depend on the level.