In the Reversed Controls Trial, putting on the blue ring will make the controls normal again. This makes going through the dangerous maze a lot easier.
In the Wall Quiz Trial after answering a question correctly, save the game, then repeat after every correct answer. That way, if a question is answered incorrectly, when it teleports Del back to the beginning, put of the green ring. This will kill Del, but it starting the saved game back up will put Del back at the wall he left off on. This takes out having to travel through the beginning of the tower all over again.