I like to imagine every one looks more or less like their avatars. Unless they have a landscape or something instead of a person, in which case I imagine them to be like Barrow Wights of different shades and sizes... Then again there is the infamous Gil-Gallad, I wonder if he looks like that avatar in real life!
And of course Morsul probably looks like Willy Wonka

Unless I'm mistake, in which case I've been living a lie my whole life. (Or death as the case may be).