An informative blog on hash tags.

(Re-pressing from the Writer Unboxed blog. By Annie Neugebauer)

http://writerunboxed.com/2013/09/14/everything-you-need-to-know-about-the-hashtag/#more-24090

If you spend any amount of time on the internet, you’ve probably seen people using words or phrases with pound signs in front of them, #like #this. On Twitter, this is called a hashtag.
Putting that symbol in front of a word turns it into a searchable link. In other words, you can then click on that #hashtag and see the tweets of everyone else also using it. It’s a way to find people talking about the same thing you’re talking about; it creates a larger conversation all in one feed.
How to Make One
There’s no trick to making a hashtag. You don’t have to register it, log it, or reserve it. All you do is type it, and Twitter will automatically turn it into a clickable search term.
Start with the pound sign (#), but don’t include any spaces or special characters (?’!&, etc.). Spaces and special characters will break your hashtag.
So if you want to use the phrase “author’s choice,” you would need to write it as: #authorschoice or #AuthorsChoice . Neither #author’schoice nor #authors choice will work properly. Some people use caps to make new words easier to read, but this is optional.
Numbers are okay, but don’t start your hashtag with numbers. #2013Conference won’t work. #Conference2013 will, though.
And lastly, don’t forget to keep it short. Hashtags do count toward your 140-character tweet limit, so the longer they are the less space you have to add other text.
Best Ways to Use Them

First, check to see if the hashtag you want is already in use. Depending on what you’re going for, an already in-use hashtag could be a good or bad thing. If you just want to join a larger conversation, you probably want to choose a popular hashtag with a fast turnaround (lots of new tweets coming out). If you’re trying to promote a contest or new chat, you’ll want a hashtag that no one has been using lately to help keep out irrelevant tweets.
Hashtags are great to start a conversation if you have enough clout to make it work. Say you want to hear what people have to say about a new trend in publishing. You can gather the talk into a central spot with a hashtag.
Other useful options include running competitions, like #PitchMadness, starting open chats, like #WritersRoad, or building buzz for your own book by creating a specialized hashtag for fans and supporters, like my friend’s use of #OMGen.
You can also, of course, jump into any existing conversations, including trending topics. The list of trending topics changes regularly, and is on the left side of your timeline on the Twitter website. If any of these topics are relevant to you, you can join the talk on those extremely popular hashtags. This can be a good way to reach more people, but it’s also easy to get lost in the hub-bub, so don’t spend too much time trend-chasing.
All of these are great ways to find and gain new followers. The idea here is to discover people who are talking about the same things you’re talking about. Hashtags can also help relevant peeps (your target audience, if you’re talking about the right things) find you.
And finally, hashtags can also be just for funsies. (Yes I said funsies. Deal with it.) Hashtags can occasionally get ridiculous. Because of this, people like to make fun of them with #SarcasticHashtags. You can use a hashtag to add a punch line to a tweet, clarify your joke, poke fun at yourself, or whatever else might make people giggle. There are also occasionally silly hashtag games that pop up, like #boozebooks.
Worst Ways to Use Them
Using too many hashtags in one tweet makes your tweet look like spam. A single well-chosen hashtag is more powerful than three weak ones.
A single well-chosen hashtag is more powerful than three weak ones.

And remember, hashtags show up as links, so if you have an actual link in your tweet you should use hashtags even more sparingly. My rule of thumb is one or two per tweet, never more than three. If your tweets look like link soup, people will blow right past them. In all the clutter of Twitter, people want less noise and more humans – not hashtag robots.
Likewise, don’t use too many hashtags in your Twitter profile bio. It looks cluttered and can even come across as tacky and desperate. The words in your bio will make you show up in relevant searches even without hashtags, so there’s no need for this. My preference is zero hashtags in the bio, but if you have more than two I would definitely suggest an update.
If you auto-tweet, don’t use the same hashtag each time. It makes your identical tweet show up in the same hashtag timeline over and over. It’s basically spam. Spam is bad. [Related tip: change your hashtag every time for shared blog posts – both your own and others’. So if you manually RT a friend’s tweet, changing the hashtag might reach different users, which is the whole point!]
And the last big no-no is hashtag abuse. You can actually get into Twitter trouble (eep!) by misusing hashtags and/or trending topics. If you use irrelevant hashtags of any kind in an attempt to get more attention in a feed that has nothing to do with what you’re saying, you’re misusing hashtags. If you’re going to use a hashtag, it must actually be relevant to your tweet. In other words, you shouldn’t tweet something like: “I love #MileyCyrus! Read my fantasy novel FREE on Kindle!”
Some Favorite Hashtags for Writers
#FridayReads – Share what book you’re reading this week!
#WriteTip – Find and give advice on tricks that work for writers.
#AmWriting – In the process? Use this tag to find other drafting writers. (Use sparingly.)
#Writing – Anything and everything to do with writing! (Again, use sparingly, or your only followers will end up being other writers. The goal is to find readers, remember?)
#AskAgent – Have a question? Ask in general and hope for an answer, or wait until a specific agent announces they’re doing an #AskAgent session.
#PubTip – Find or give advice about the pub process from those with experience. (But be wary, because like all advice, some is good and some is not.)
~*~
Still have questions about hashtags? Ask in the comments and I’ll do my best to answer!
Writers, what are your favorite hashtags?

Annie Neugebauer is a novelist, short story author, and award-winning poet represented by Michelle Johnson of Inklings Literary. A member of the Horror Writers Association, she has work appearing or forthcoming in over two dozen venues, including Buzzy Mag, The Spirit of Poe, Underneath the Juniper Tree, the British Fantasy Society journal Dark Horizons, and the National Federation of State Poetry Societies’ prize anthology Encore. Annie lives in Texas, where she pretends to battle a blissful addiction to Dr. Pepper.