Training Videos 3d Interaction with live action

Ok here's the story:
Doing some training vids where there's going to be things happening in the background that interact with the speaker in the foreground (who is simply going be filmed infront of a green screen).

Is there any resources out there, hints, tips, tricks or inspiration out there of 2d and 3d interaction with live action that anyone could recommend pretty please?

I'm not looking for seamless integrated vfx you see in big budget movies, more rather the presenter playing with the bg and the bg playing with the presenter, I guess an example of this is in Jurassic Park when Hammond explains how the DNA process works to create dinosaurs he interacts with MR DNA on the screen in order to create clones of himself. That's the sort of ideas I am after.

Thanks a bunch you peoples!