Trying to prune and maintain the All feed is a huge task at the moment, especially since some content might be the type of stuff you want to see sometimes, so just blocking News or Memes isn't a perfect solution.

Having Tags for posts for easier filtering would be great, but right now sticking to a carefully selected subscribed feed has been easier, for me at least.

There are some apps - like Connect and Sync - that allow filtering keywords, domains and entire instances, should you want to try to control your All feed.