You are your child's number one advocate. If something helps your child at home, during transitions, or to get through the day, it is important to figure out how to bring that item into the classroom so your child feels safe and secure in the classroom. However, we also do not want to be disruptive to the other children in the classroom so we must make sure we take into consideration others' needs as well.
If your child has sensory concerns such as too much noise on buses and when eating in a noisy cafeteria a simple and quick fix is sending in noise-canceling headphones. These work great and will help your child tolerate noisy environments.
Sending your child with a sensory toolbox is a great idea. I often tell parents to put fidgets, stress balls, theraputty, essential oils, and chewlery in a small box that can be kept in the back of the classroom or even your child's desk. When your child requires a sensory break, they ask the teacher through a signal (can be a secret sign like a thumb up or an “ok” or even an index card they hold up), that allows them permission to have a break. I have also tied theraband to the bottom of chairs to provide stimulation when kicked. There are lots of ways an Occupational Therapist can implement a sensory diet into the classroom for your individual child's needs.
For children who have a difficult time sitting still, I have often sent in weighted dolls that can sit on their laps to help them sit still. Weighted vests or weighted socks that can go on their shoulders or a disc to sit on (a round cushion that inflates and provides vestibular input when seated on).
Communication with the teacher is key. You want them to understand your child's needs and how to help them without being disruptive to the other children. By sending your child with the proper tools, you are providing them with an opportunity to be successful and gain confidence.