Which are two recommended methods of creating test data in Salesforce?

Utilizing Heroku Connect to provide test class data is not a recommended method of creating test data in Salesforce, as it can introduce unnecessary complexity and dependency on an external system. Referencing data from middleware directly within your test class is also not a good practice, as it can make your test class unreliable and dependent on the availability of the middleware. Hosting a mock endpoint to produce sample information from an endpoint and loading a CSV as a static resource and referencing it in a test class are both valid methods of creating test data in Salesforce, as they allow you to isolate your test class from external factors and ensure consistent results. See Create Test Data for Apex Tests for more details.