Scramble Squares are puzzles involving nine squares. Each side of each square holds half of an image that can be completed if it's joined to a corresponding side. The basic gameplay is simple, but the puzzles can be very difficult to solve, considering that there are billions of potential ways to rearrange them.
Count the pairs of each image
Most images have a front end and a back end in Scramble Squares. For example, if animals are involved, one side has the head and the other has the tail. For each image, figure out how many front and back ends are present. If there are more front than back ends or vice versa, you know that some of the surplus side tiles will end up on the edge of the puzzle where they will not need a match. If you find multiple extra sides on one tile, keep that tile in mind as a potential corner piece.
Eliminate piece pairings that can't work
Start with the pieces that have the sides that have the fewest match options. Test some of those options and see if they create any inside corners that cannot be filled with any other tiles.
Guess and check potential answers
Look for patterns and try out different tiles in different places. After you have made some educated guesses, much of the puzzle work simply involves trying as many options as possible. If you feel stumped, search online for a hint or a solver.