To block twitters really annoying trends and user recommendations use the following custom filter:
Updated via @emaleroland
twitter.com##div[class*="flex-module trends-container context-trends-container"]
Old:
twitter.com##div[data-component-term="user_recommendations"]
twitter.com##div[data-component-term="trends"]
I’ve created a filter list you can import into adblock plus. You can download it here - https://github.com/digital006/socialcrapremover
Feel free to fork and commit additional filters