Before you just crack on with adding tens of property settings, spend some time designing the user experience and the flow on how a user can navigate and meaningfully define its parameters. The purpose of a well-designed property panel is to promote reusability of the same code base for different use cases. User adoption is critical to the success of an extension, and it must be easy to use, with as little training as possible. Qlik Sense has powerful self-service capabilities, and for them to be appropriately leveraged, extension objects need to be just as easy to use. 

As such, the following are some tips to focus on when working on the property panel, which will improve the user experience:

• Use Qlik Sense custom components, such as sliders, button groups, and drop-down lists as much as possible.
• Put the most relevant extension settings in the General Settings tabs. Split individual settings into sub-categories.
• Follow the user flow when defining extensions: they begin with dimensions, then metrics, then design and appearance. Make sure relevant settings are found in the respective sections of the property panel.
• If a user has to ask you where to find a particular property- rethink the property panel.
• If there is a discussion during requirements gathering whether a chart should have this feature or not-implement it as an option in the property panel and make it dynamic.