There are three important aspects of a question post at Stack Exchange, and you shouldn't neglect any of them. They are the title, the question body, and the tags.
This is the advertising for your question. This is what people will see in the question list on Stack Exchange, as well as in the search results in web searches such as from Google. The title should have enough information in it so that someone can immediately tell if they're likely to have the answer or if it is the same sort of problem they're having, but not so long that the information takes too much effort to parse. (Save the bulk of the information for your question body.)
Good question titles are often in the form of a question, but not always. The title should be a complete sentence, or near to. Examples:
- BAD: gmail filter problem
- GOOD: How can I filter Gmail messages based on the sender's domain?
- BAD: facebook privacy questoin
- GOOD: Change default for future posts on Facebook to be "Close Friends"
One other piece of advice: Don't use "tags" or "tag-like" constructs in your title. For one thing, the most used tag on your question gets added to the HTML title of the page, so it is displayed in any search engine lists. It's okay to specify the web app you're asking about as long as it naturally fits. (More about tags later.)
- BAD: Twitter: search direct messages
- BAD: [Twitter] search direct messages
- BAD: Twitter - search direct messages
- GOOD: How to search Twitter direct messages
If the title is the advertising for your question, this is the pay-off. It should stand alone; a person reading your question body shouldn't have to refer back to the title. It should also contain everything a person would need in order to answer it. It's fine to link to outside resources to provide extra information or to give credit to a source, but don't require someone to follow such links in order to be able to answer your question. Similarly, images can be a great way to help illustrate your question, but it's best if your question doesn't depend on the image. Be kind to people with vision impairments, or those otherwise can't see images.
Make your question easy to read. Non-standard English makes things difficult to read for native English readers, and much worse for non-natives. If English isn't your first language, do your best; the effort is noticeable. If you're taking shortcuts like leet-speak or txtspk, stop. Yes, it may save you a bit of typing, but it makes your question all that much harder to read. You don't want to turn away someone who might know the answer to your question. Besides, you have far more than 140 characters in which to express yourself.
Use Markdown formatting to your advantage. Be sure to break up your question into short paragraphs of just a few sentences each. Unlike print, when reading on the web, people scan rather than read deeply. If they encounter a "wall of text" they may not bother to read your question. Also, use Italics and bold text sparingly, if at all. Use them for emphasis if needed, but don't overdo it. Similarly, don't USE ALL CAPS FOR EMPHASIS. In online communication it looks like shouting, and is a throwback to typewriters when it was the only way to convey emphasis.
Lastly, your question should contain just your question. You're not writing a letter to a colleague, you're creating an entry in a knowledgebase. Don't use greetings ("Hi!", "Dear sir", "hey guys") or a signature or signoff, and avoid phrases that attempt to address the reader, like "thanks in advance". It's all just noise that distracts from the question. Besides, every post you make has a user card with your name, avatar, a link to your profile, and some other information. And we would rather you thank people by accepting answers, upvoting good posts, and answering some questions yourself.
Finally, there's tags. Tags are how to categorize the topic of your question. This makes it easier for experts on that topic to find your question. Here, you're presumably asking about a Web App, so a tag with the name of the app is key. (Examples: gmail, facebook, cognito-forms) In many cases, that may be all you need. For some large/popular apps, there may be tags for specific features, like gmail-search or facebook-pages. (And if you're not asking about a specific web app, it's very likely your question is off-topic here.)
What you shouldn't do is use tags that don't categorize your question. Yes, you may have a question about Gmail, and you use Google Chrome, but that doesn't mean you should add the google-chrome tag to your question.
Also, avoid what are called "meta tags" they're tags that are overly broad and can't work by themselves on the question. A tag like "post" is not very useful. There are many web apps that have the concept of a post, but without knowing the web app in question the tag has no meaning. There are no experts on "posts". (Except perhaps fence builders.) A good guideline is: if a tag can't adequately categorize the question all by itself, it probably shouldn't be used.
You can have up to five tags on a question, but don't feel pressured to use all five. In most cases, just the tag for the app you have a question about will suffice.
If you follow this advice, you're well on your way to writing great questions that attract upvotes, answers, and, even better, help other people in the months and years to come.