Take every single aspects of what you really like from the original mario games and make a level entirely based on that!

my humble advice: present one mechanic or two to the player and then ellaborate on that, this helps make the level a cohesive piece and not a doodle.

Hello fellow citizen, I recommend decorating. Use whatever blocks you'd like, whether that be question mark blocks or hard blocks. Just make sure not to go overboard. Sincerely Obama.

make a level based on an enemy or gizmo. goombas, koopas, even bowser if you want to!