What are the best practices for using the {% cache %} tag?
Generally you’ll just want to cache areas of your templates that are going to trigger a lot of database queries, or fetch a lot of data, since those are going to have the biggest hit on your site’s performance. Matrix field loops that have relationship fields inside them (Entries/Assets/etc.) are a good example, since each Matrix block is going to come with one or more DB queries.

There’s not much advantage to caching less intensive areas of your templates, and might lead to unexpected consequences, if you have anything dynamic being output that’s not pure-content, such as the logged in user’s username.


  ..to combine the cache-tag with other supported caches?


Worth mentioning that template caching does not respect the cacheMethod setting – that’s just for data caches. Template caches always go to the database, which in this case is the most performant option.