Between each
Here's a grammatical construct I see fairly often in submitted stories:
* There was a gap between each of the books.
* A divider separated each shoe.
* Put a blank line between each paragraph.
I view these as mistakes. Using this sort of construct is an easy mistake to make: I often find myself wanting to say that last one, for example. But each refers to each individual item as a single thing, while between and similar words should (imo) be used to talk about two or more adjacent things.
So I advise rewriting in various ways:
There were gaps between the books.
There was a gap between each pair of books.
There was a gap between each book and the next.
A divider separated each shoe from its neighbor.
Put a blank line after each paragraph.
Use blank lines to separate paragraphs.
Use blank lines between paragraphs.
And so on.