Hear are some techniques so to speak I use when playing this game, and yes, I have reached five stars, even on maximum difficulty
Seriously, this is helpful. These are the easiest pieces to find, and they allow you to buld the edges and get a decent grasp of the picture early in the round.
Upon finding your corners, it is wise to build the rim of the puzzle first, as these pieces, in addition to being easier to place thanks to the border pattern and the ability to establish which side of the puzzle the borer piece is on based on where the border portion is within the piece (if the border pattern is at the bottom, this piece goes on the bottom, etc.) It should also be noted that the unique border pattern allows one to figure out which pieces lie next too each other
Only switch pieces if you are confident in your placing, and if you guessed wrong, switch them back
I cannot stress this enough. The pieces in the puzzle are not randomly placed, rather they have been switched with another piece. To elaborate, if you move a piece to its proper place and have not moved the piece in that place, both pieces will now be in their proper places. It is extremely detrimental to leave pieces in wrongly guessed places, as you then lose this advantage so always be aware of what you are moving where so that you can reverse your action if you are wrong.
If you can, follow the beginning sequence
Although extremely fast, the beginning sequence will show you both the solution to the puzzle, that is the picture you desire, and all the switches. Even catching just a couple of the switches is helpful.
To be honest this is the hardest for me. There will be distractions, the randomly appearing NFE, the sudden and abrupt shift in camera angle, and the interesting Pokemon animation. You must be ready for the camera angle to shift at any time, and be speedy in switching when the camera angle shows you a potential switch. And as much as you wish to appreciate your cute and or cool Pokemon (I know I do), you can do that with the picture at the end