Depending on where a level stands compared to the rest, decides for a big portion how well that level works. It may be too difficult at an earlier point, or to easy at a later one. If you find yourself tweaking a level to no end to make it easier or more understandable, the problem may need lie in the level itself. Changing it’s level placement can have a huge impact and make the level achieve its desired result. For more, here’s an interesting article on the puzzle placement in Metrico.
You can also try to divide up the steps in the a particular level to multiple levels, making it easier to understand. Nintendo likes to do this, you can see a really good breakdown on this youtube video Super Mario 3D World’s 4 Step Level Design by Mark Brown. Essentially, they introduce an concept, develop it, twist it and bring it to a final conclusion. This is a structure is inspired by a narrative structure called Kishōtenketsu. You see this often in Chinese, Korean or Japanese stories, but can just as well be applied to games. You can see it in one level, a series of levels or even in the structure of the overarching stages.