My inspiration actually comes from a variety of things. Life can feel kind of "meh" sometimes, and you might think that doing thing x isn't going to produce result y, so it gives you no incentive sometimes to make something or start a project.
I'm actually making a full episode on a few ideals I haven't seen majorly used in most SMBX episodes, and I really want to make/complete it because I thought through how platforming/adventure/item collection games never really die, as long as there are new ideas and content, players will keep wanting to do more with it. I wanna make a great episode that makes players feel something new with SMBX (mario games/platformers in general) that will definitely be worth the effort in the end. I think of episodes like Apocalypse of Foroze or Eternal Chaos and just think of all the time that went into those, and think "I really really want players to have more eps that feel this dedicated".
The thing is that I'm also new to the editor in a way, so I'm learning new stuff, and although I'm struggling a bit with certain functions, I'm willing to brace the hardships and do it right rather than cut corners because I want an episode that will be remembered.
The question really is why do you want to make a level or two, and what can you do with it that doesn't make it feel like a dry level? Themes and gimmicks are always awesome to come up with, especially if you're just doing a level or two.