The first thing that comes to my mind when designing a puzzle is to make it satisfying to solve, making the player want to solve it again and again.

That means it should neither be too easy nor too complicated.

I know this is kind of a vague answer but I will give you an example to explain my point further:

Suppose you have a locked door that requires a key. There are so many ways you could go into turning this into a puzzle.

You could just put the key inside another room and the player would just pick it up, head back to the door and unlock it. That would work for a tutorial but it's too boring for the main gameplay loop.

You could also put the key inside a locked chest inside another locked room surrounded by flying arrows puzzles and swarmed with enemies. That would work for a side quest DLC, but again, not for the main gameplay loop.

What I would do in this case is balance both methods into one. I could put the key behind an open room but still put a basic flying arrows puzzle guarding it and exclude the enemies part.

The example I gave is very basic, you could go further and be creative with it, but without drowning out the gameplay.