Qlik Data Modelling

Your goal should be to create a data model that enables efficient handling of the data in Qlik Sense. Usually this means that you should aim for a reasonably normalized star schema or snowflake schema without any circular references, that is, a model where each entity is kept in a separate table. In other words a typical data model would look like this:

• a central fact table containing keys to the dimensions and the numbers used to calculate measures (such as number of units, sales amounts, and budget amounts).
• surrounding tables containing the dimensions with all their attributes (such as products, customers, categories, calendar, and suppliers).

Qlik Help Reference: http://help.qlik.com/en-US/sense/Subsystems/Hub/Content/LoadData/understand-data-structures.htm

Qlik Community serves as a good resource on best practices shared by Qlik developers and data architects. The community post https://community.qlik.com/docs/DOC-9040 has a good starting point of cross-references to introduce various basic and advanced topics related to data modelling. 

The Qlik Design Blog covers various angles of working with data modelling and visualizations in Qlik products.