Disciplined skimming to cover (or skip) material faster when that makes sense, can save much time. And *writing* for it, to help others.

• In my opinion, "tl;dr" is not necessarily the answer: the word is "summary" which is a useful tool. Clear writing and *disciplined skimming* can be helpful.
• For reading and writing essays, some web pages, or academic papers & books
• For reading news articles
• For reading an outline, read only the most out-dented parts, and then the indented parts only if interest in the parent entry justifies it.
• For additional suggestions, see this link (wikipedia.org; content is there at least as of 2018-9-6) including the references:
• ...or if the links are broken, search the internet for "how to read an academic paper".
• Possible other references & thoughts (about skimming effectively & writing for it)
• Like with so many things, this gets easier with time and practice!