Provide executable examples
Provide executable examples that users can type directly into their terminals to see working API calls. To the greatest extent possible, these examples should be usable verbatim, to minimize the amount of work a user needs to do to try the API, e.g.:
$ export TOKEN=... # acquire from dashboard $ curl -is https://$TOKEN@service.com/users
If you use prmd to generate Markdown docs, you will get examples for each endpoint for free.