Is there a tutorial out there for them? I've done a lot of digging but can't find one.

There's not much to the clips. For the corner clips, just get a running start and duck jump, aiming for the ceiling about half a tile before the corner. For the 1-up clip, just trigger the block then duck jump around and onto the block.

I am also going to add: First clip, hold right when you hit the far wall to clip through.