What makes a tag the most useful? I see all sorts of variations of the same words and combinations with _ or -
In short, there is inconsistency and a lot of clutter.
Is that a problem for conducting good searches? If so, what guidelines should be used for creating tags?
And worse, you can’t fix a tag if you discover later you’ve made a typo.
Can’t you Retag?
There is a lot of clutter, but as you can’t contact moderators, or anyone else fo r that matter, it’s hard to get it cleared - you have to agree on rules for tagging to prevent people retaining the same tags over and over.
Are there guidelines used in other forums that could be applied here?
I agree that is a problem to not be able to change tags. I just realized that I should have used “meta” rather than “common” as a tag here but alas, the retag function does not appear to work.
I retagged the question by clicking “retag,” changing the values and pressing Enter. It requires 50 karma points, so you should be able to do it.
Jim, when I try what you suggest, my edit does not get saved. It sounds like ajlittoz may have the same problem.
I also tried to retag and it didn’t work.
I just discovered you need to type return inside the tag line to save the edit
Works for me now. Maybe typing return inside the tagline is what made the difference (although I would think I did that before). Thanks for the tip!
What guidelines should be used for creating tags?
Tag which component the question applies to: writer, calc, base, impress, math. Don’t use common unless it is important to indicate that it applies across components.
EDIT 2018-May-21: Quoting a wiki error message, “At least one of the following tags is required: common, writer, calc, impress, base, draw, math, or meta.” So there is no choice but to use common in many cases.
Add other applicable tags. These may include:
Don’t use non-applicable tags to draw in more readers. There is no need on this site, as it’s possible to browse all new questions. A good number is perhaps 2 to 6 tags, depending on which tags apply.
Research tags on this site to see how they are most commonly or appropriately used. Have a look at the most popular tags. For example, I would choose styles over style because it is more popular.
Use tags from other better-designed sites.
There is a related question at On guidelines to tagging and avoiding unnecessary tags - Meta Stack Exchange.
What makes a tag the most useful?
As @MarkMcLean said, tags help find related questions about a particular topic.
Tags also provide more information about the question. So, if the question is “How do I write a macro to say Hello, World” then the answer will be different depending on whether it is tagged writer or calc.
I see all sorts of variations of the same words and combinations with _ or -
On occasion, I go through each variation for a particular tag and then retag to standardize. Click 
, change the values and press Enter. This requires 50 karma points.
However, this site’s flaws make it difficult to encourage consistency for tags, so in many cases, this may not be practical. Fix the tags that are most important to you.
Is that a problem for conducting good searches?
To some extent, although searches can be performed on full text to avoid this problem.
Thank you for the informative answer. However, I am unclear what you mean by
“On occasion, I go through each variation for a particular tag and then retag to standardize.” What exactly do you do?
tag2. 
Does one of these steps fail to work for you? Perhaps you did not press the correct key on your keyboard.
Well, for some reason this works now. Perhaps I wasn’t clicking inside the box, as ajlittoz suggested above. Anyway, I was trying to understand how you know what are standard names for tags. Then I found that by clicking “Tags” at the very top, I can see a list of what appear to be the most commonly used tags. That must be what you were referring to.
“…clicking Tags at the very top… must be what you were referring to.” Yes, that’s where the link in my answer is from. It shows all tags sorted by how many times used.
Most useful tags are those that let you quickly search/browse for a problem similar to yours. IMHO, however, the problem here is not about tags specifically but about the design of this site generally. The design is great for a forum of hackers (or simply clever users that know the true meanings of RTFM and STFW), but it turns bad for a forum full of lusers that behave like if they were on some crappy social network site.
A hacker/clever user does RTFM and STFW first, then comes here and:
A luser does not RTFM, does not STFW, does not browse/search the forum, simply asks a stupid question, makes a loooong title, then makes a loooong list of tags because (the logic of a crappy social network site) more tags means more visitors and more likes. I have seen a hilarious example when a moron put an entire post (not even merely a question) into the title field and then into the tags field.
what guidelines should be used for creating tags?
True lusers don’t read any guidelines 
I believe, the tags feature should be limited to, say, five words. And the length of titles should be limited too.
I am not sure who you are directing your answer to. There are many people using these forums who are not “losers”. If people like me who are not techies could learn what best practices are, then perhaps tags would be more useful. Maybe not, I don’t know. But I would like to know people’s ideas.
It sounds like you don’t have any advice about tags, other than to limit the number. But surely the appropriate number would depend on the question.
Sounds like you have had some bad experiences. Have you considered using the passion of your frustration to help improve the situation?
It sounds like you don’t have any advice about tags, other than to limit the number.
It sounds like you are challenged by reading a relatively simple post of mine. I can’t help this situation.