1) Keep it Simple: Tweets are limited to 140 characters, so each one has to count. Keep hashtags as short as possible, but also as simple as possible (easy-to-spell words, common characters, etc.). Consider, also, that the people participating in the discussion are likely doing so via mobile devices – so the less they have to key in, the better. Better to add a letter than use a character like an underscore, which requires smartphone users to press two buttons (shift/function + the assigned key).
2) Consider Outside Audiences: One of the reasons to use hashtags is to promote an organization, topic or event to people who aren’t familiar with it. If this is one of your concerns, make sure your hashtag is intelligible to people outside your organization.
3) Don’t Redefine the Lexicon: Changing the language people use is exceptionally difficult, much like swimming upstream to spawn (or at least I would assume – I’ve never done it myself). If words already have widely-accepted meanings, stick to them. Communication is only possible because we all agree that symbols (ie words) carry certain meanings.
4) Step Back and Read Your Hashtag: Before you launch a hashtag, check it first. In our quest to be brief, we often create acronyms that are problematic. My favorite example (and also one of my favorite Twitter discussion groups) is #prStudchat. It’s an online discussion for students (which I highly-recommend) – but it has the unfortunate quality of looking like an erotic discussion forum. Fortunately that hasn’t hurt their content any, but you can imagine the ramifications if a different group with a more conservative bend were to expose themselves to ridicule with that sort of tag.
5) Index Your Hashtag: Frequently the events or issues we want to discuss are reoccurring. If it’s appropriate, add a date, location, or some other distinguishing feature so that one iteration of the discussion can be kept separate from another.
While we’re on the subject of Twitter – if you haven’t seen it already, there’s a pretty smashing database of hundreds of Twitter chat events that require only a hashtag to participate in. Check it out at www.bit.ly/chatsched