My daughter got some ABC and Numbers puzzle that are slightly bigger than her age when all put together at a single set. So, I bagged them up into zip locks and labeled them. I divided the ABC puzzle into six sets according to the Montessori language divisions; SMAT, BFOX, HUCP, NERD, WIJGL, KQVYZ.
I divided the numbers into 5 piece sets; 1-5, 6-10, 11-15, 16-20 since she is getting really good at 1-4 and should be up to 5 soon.
I like buying materials just a little bit out of her grasp and the pairing them down like this. 1. It pushes her and 2. It saves money because I can use them longer. I also got these three wooden puzzles on sale, I think individually that they might be easy for her so I put them into one container together. I used a Montessori trick- "control of error"- to help her discern which pieces fit to which puzzle. I put all dragon fly stickers on the dinosaur puzzle, all heart sticker on the duck puzzle, and all animal stickers on the lion puzzle.
I know that these tricks are not belonging to Montessori alone but they are valuable, you can use anything that you find and make it fit your child/children's abilities. Happy teaching!