I'm loving anything thrifted, handmade or repurposed. There are some lovely Montessori materials that I'm going to invest in but I like to DIY a few things too! Here are three DIY materials that we are currently using and loving with Otto at nine months. These are suitable with supervision once the infant is sitting, perhaps from 6-12 months+.
Above is a ball tracker made from an egg rack (similar here). I've seen this used a few times in Montessori toddler rooms, but I can't find any examples right now. Unlike traditional tracking toys, the infant isn't tracking from side to side (building up those eye muscles) but is simply tracking the ball down the egg rack. It's a lot of fun and it's also good for coordination and concentration. We've used a repurposed egg rack (also known as an egg helter skelter) and some wooden balls. We simply put the ball at the top and watch it roll down to the bottom.
Neutral, texture fabric squares. I made something similar for Otis here, but as I don't have my sewing machine with me I've used pinking shears around the edges. The idea is that the squares are all the same size and a neutral colour, allowing the infant not to be distracted by different colours and focus the textures. I've used fabric found around the home including felted wool, terry towelling, linen, cotton, brushed cotton and calico. Otto mostly takes these out and puts them back into the basket but occasionally you can see him softly feeling the fabric and running his fingers over it. Inspired by this post and these fabric squares. Similar can be bought and later used for matching.
Sensory shakers. Again, I made similar shakers for Otis here. Otto loves rattles and these are fantastic as each shaker has a different weight, feel and sound. I like to use old spice jars as they are recycled materials and fit nicely in the young child's hands. Ours are glass but I feel like plastic spice jars would work too. I like to use natural items that aren't going to perish such as dried beans and pasta. What is important is that each jar is different. The nutmeg provides a solid clunky feel and sound while the little pasta pieces make a finer and softer sound and feel.
At the moment I'm only presenting three jars at a time in a basket and rotating them when Otto loses interest! Otto likes to bang things together but doesn't like the sound and possibly the feel of banging these glass jars. You can superglue the lids closed for safety however, I only use these under supervision and will continue to reuse the jars.