Hi Willy De la Cruz Sierra, thanks for your feedback.
I know the doc is not extensive at this moment, unfortunately.
I tried to create new examples in this branch, so please take a look there.
In a nutshell, the idea is to create small functions that return or do something. Then you can expose them directly as your base test function, or you can create a new one on each test file in base on your tests.
For instance, you can create a reusable fixture, if this fixture is required in most of the tests, or create a specific one if the fixture is just for one or two tests in the same file.
Let me know if the examples are clear; in case, I'll try to be more exhaustive.