At this point there are traps that can hit the player, teleport the player, apply blind satatus or make player loose focus.
Actually traps might also apply statuses to player, such as bleeding, poison, hexed, etc. and maybe, the most cruel - immobilization (absolutely no problem usually, but a disaster in case the room is not cleared yet and the player tries to retreat)
Also traps that damage armor/weapon or "steal" (unequip and drop, maybe in a different place) some item might be introduced for variability. On the bright side such traps may help player get rid of cursed items. Again, in case there are no enemies nearby those are just a minor nuisance (unless the items are stored far away, e.g. in an evil chest). Also spoiling the food might be another option. I'd rather not burn scrolls/books or burst potions, as they are much harder to obtain and such loss might be very irritating.