When to use JSX.Element vs ReactNode vs ReactElement?

I am currently migrating a React application to TypeScript. So far, this works pretty well, but I have a problem with the return types of my render functions, specifically in my functional components. I have always used JSX.Element as the return type, now this doesn't work any more if a component decides to not render anything, i.e. returns null, since null is not a valid value for JSX.Element. Th