How would I go about it? For example, I see a question asking "what is the fastest way to do x and y" and newer solutions have since become popular.
I do not want my question to be closed so I want to make sure I find out common practice first.
If you are aware of "a faster way to do x and y", I recommend answering the old post with the new, faster ways you have discovered.
In other words, why not simply update the question yourself by answering it?