#5. Target your audience. Ironic hashtags will always be a thing, but best practice on Twitter dictates that proper hashtags are used to target other tweeps with relevant messages.
Take advantage of the hashtag as a filing or labeling tool by indicating to the
Twittersphere who your tweets are intended for.
For example, a marketing pro could use the hashtag #marketing101 to indicate that a tweet contains marketing intel; or if you are a freelance web designer, for instance, you might want to tag those tweets that contain tips for fellow designers with #webdesigntip.
Via Robin Martin