Children learn from example.
Are you who you want them to be? This is why it is so important that you are in control of yourself, especially when under pressure. You are the adult, they are the child.
Develop a range of techniques and skills that you can use when the children are not behaving in an appropriate way.
When developing these techniques you need to keep in mind that these children need to be treated differently to others. Therefore you will need to talk with other teachers who have developed some successful techniques and you will need to think a bit outside the education square.
Be aware that these children may have difficulty with non-verbal communication so tapping your foot, hands on hips with firm eye contact may not work for them. Punishing them rarely, if ever works. It has been said that the definition of insanity is doing the same thing and expecting a different result. If what you are doing is not working then try something different. This may even mean talking to the child’s parents to ask for some advice.
If you haven’t developed a range of techniques then there is every chance that when the pressure is on you will be out of control and be reactive instead of proactive.
Gain an understanding of the condition that the child has.
If you understand how and why they behave the way they do you will be in a better position to understand them and develop appropriate techniques to manage their behaviour. The flow-on effect of this will result in you being more able to help them educationally. The fact is that most of these children will only learn if they are in a safe environment with low tension levels. We accept that adults have performance anxiety but we generally don’t give the same recognition to students. If the children are constantly in a heightened state of tension/anxiety they will not be able to think clearly and their behaviour will be “off” as well as having a reduced ability to learn.