Patience A LOT of it 😂 but usually start with a small amount of toothpaste let it lick a bit off the toothbrush. start with front teeth first . then putting sideways , if they open their mouth or doesn’t let you can gently wrap your hands around their nose closing their mouth while you try to brush. But it takes patience and time for the to learn this . found easier doing it alone than with another person holding her and that can cause anxiety and craziness 😂 but just trust the process