One mechanism that is commonly used is the obvious one —
answers to other questions. 
Sometimes somebody will ask a question that strikes to the heart of an issue
and draws large numbers of high-quality answers (and comments). 
Other times a seasoned veteran of the site will ask a generic question
simply for the purpose of having a place to hang answers on. 
These are commonly tagged [tag:community-faq] (or [tag:community-faq-proposed])
in Super User. 
(Similar questions on [Unix & Linux][ul] are called “canonical questions”. 
High-profile examples include:

- [How do I add VBA in MS Office?](http://superuser.com/q/801609/150988)
- [How can I remove malicious spyware, malware, viruses or rootkits from my PC?](http://superuser.com/q/100360/150988)
- [What can I do if I forgot my Windows 7 password?](http://superuser.com/q/72244/150988)
- [How do I recover or “undelete” files that I accidentally deleted?](http://superuser.com/q/449550/150988)
- [What are PATH and other environment variables, and how can I set or use them?](http://superuser.com/q/284342/150988)
- [What are the shell's control and redirection operators?](http://unix.stackexchange.com/q/159513/23408) (on Unix & Linux)
- [How to debug a bash script?](http://unix.stackexchange.com/q/155551/23408) (on Unix & Linux)

[How do I recommend software in my answers?](http://meta.superuser.com/q/5329/150988) (tagged [meta-tag:faq] on Meta Super User) is, similarly, referenced in many comments.

If you’re feeling ambitious, write a broad question along the lines of the above and immediately post a similarly all-encompassing answer.

[ul]: http://unix.stackexchange.com