Give us the bottom line in the top line, the subject. Summarize the topic in the first paragraph. Expand the story with more details in subsequent paragraphs.
Try to tell the whole story in the subject line, the headline for your story. On this forum, the subject window only displays about 55 characters at a time, but the subject field will hold 80 characters, enough for a complete sentence. Make the most of it.
Some of us are retired and don't have time to bother opening topics that are not clear. The headline is the first chance to get the attention of your reader. In this forum, on mouse-over of that subject line, a balloon is displayed with about 8 lines of 50 characters, enough for a paragraph or two. Take advantage of that feature to provide a synopsis of your story. It is your second chance to hook your reader.

Note the progression of these subject lines:
Won't Start
Starter Will Not Turn Over
2001 California EV Starter Will Not Turn Over: Battery is New
Which subject line do you think is likely to extract a helpful reply? The third one of course, and only about half of the available 80 characters were used.
Finally, flesh out the story with more details, images and links. The Government Accounting Office uses the inverted pyramid. The title of their report is the conclusion of their work. The first page has a one paragraph summary. The next page is an executive one page summary. Then the voluminous report follows.
More info on the Inverted Pyramid style of writing.In other words, unless you are writing a fairy tale, give us all a break and use the journalism style of writing, the inverted pyramid.