"an efficient way" is correct and usable in written English. You can use this phrase any time you are referring to a method that is efficient or effective for achieving a goal. For example: "Creating an online survey was the most efficient way to gather feedback from our customers.".
wanted an efficient way to consolidate them.
It's certainly an efficient way to introduce the characters.
It was not an efficient way to harm or kill.
It is an efficient way to absorb the information.
For providers, it can boost sales in an efficient way.
It is an efficient way to minimise your information costs.
"We expect them to act in an efficient way".
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com