There are two major mistakes leaders make when delegating. The first and by far the most prominent is not to really delegate at all. Sure tasks are assigned but responsibility with authority is not. The other extreme is to give responsibility and walk away, only to wonder later what went wrong. This Forbes post is a great process:
Too often leaders conclude their task assignment/delegation process with the most useless question on the planet , “Now, do you understand?” or the equally impotent “Any questions?” The simple truth is that both questions feel rhetorical and don’t tend to elicit any authentic feedback on the recipient’s true level of understanding or comfort with the task they’ve just been assigned.