The DMG provides special Optional Rules to cover the unique effects of each plane, such as the Feywild being able to warp your memories and shift time on you, or the Beastlands turning you into an animal and increasing your hunting skills, or Ysgard allowing you to fight to the death and come back, Hades turning you into a larva, the Abyss and the Nine Hells changing your alignment to their flavor of evil, and so forth; just point the players towards these and that gets all the flavor of being in the planes across without the overabundance of rules that each plane had, and without being quite as lethal as AD&D.
You know... just a little bit more guidance on that, combined with some random elements-- "what, you thought you knew something, cutter?"-- could make something delicious.