It’s also perfectly fine to ask and answer your own question, as long as you pretend you’re on Jeopardy! — phrase it in the form of a question.
I do it all the time! For example, when I ran into a nasty issue with Java exploits in Google Chrome when browsing for images, I documented that on Super User by asking and answering my own question. Now, others can benefit from my misfortune — and best of all, I got new even better answers beyond what I offered! Overall, a huge win all around.
On a project I’m working on at my current job, I’ve come across some really pernicious problems where there is either
I’ve kept these issues in the back of my head and, now that that part of the project is winding down and the issues are resolved, I plan to go on Stack Overflow and create a high-value question and answer pair for each issue. That way, the next person who has the problem won’t have to slog through so much misinformation. I might even learn some more about the various issues that plagued us if other experts chime in with their own knowledge.
Bottom line — never hesitate to ask and answer your own question on any Stack Exchange site. Please do! It’s all part of our shared mission to make the internet better.