Providing a self-correcting control for the child is key in a Montessori environment. In the case of tessellations, generally the only control is in the presentation and observation.
A more independent, self-correcting control is available by providing an inset board for the tessellations. The inset board should be designed so that it holds a tessellating pattern. The child then can remove the shapes from the board, and then refill the board. In order to refill the board, the shapes must be aligned in a tessellating pattern.
Then, when the child is ready, they can abandon the board and do the tessellations independently in a conventional sense.