I spend 3-5 minutes thinking before writing - I do it to support a good argument even though many of them don't consider it a quality post. Thinking before writing is recommended because by doing so you have tried to convey something that can at least be justified by your own thoughts regardless of your knowledge or other people's judgment.

Writing something long does not mean it has quality – actually something quality is not just a long piece of writing but really depends on the information you want to convey and how useful your post is. All qualities are rated by other users - you, me and all other users just write and let them judge it.