Q:

How to use rendering variants as reusable component?

I am looking to create reusable container section with promo rendering variants. This section should include multiple variant rendering. For example, a section with partners logo which I can reuse through out the site. 
What is the best approach? Partial Design, Reusable components (rich text/HTML)??, or snippet? page content? or anything else. Thank you

A:

Partial Designs
You can use the partial design for the outer sections. like grey section containers, read section containers and black section containers. Those are constant ones. Read more at:
https://doc.sitecore.net/sitecore_experience_accelerator/designing/page_design/page_designs
Snippets
Rest of the part which is static one and repeatable on multiple pages, you can create snippets. There are 3 configurations for the snippets. you can find here:
https://doc.sitecore.net/sitecore_experience_accelerator/working_with_content/sharing_content/select_modify_and_create_associated_content.
Unassinged Datasources
For those Rendering Variants that contains the rendering parameters coming from page level, for example ( page content component ), you can set the data source for those components to empty and assign the parameter in the rendering variant. you can check more details on:
https://doc.sitecore.net/sitecore_experience_accelerator/building_the_layout/renderings/the_sxa_renderings_and_rendering_variants

