Not to do

Don't choose tunes primarily because of the lyrics, title or clever name of the band.  Most dancers don't listen to the lyrics when they dance.  Dancing is a very non-verbal activity, so choosing a tune primarily because of its lyrics has almost zero value to the dancers.  Besides, dancers come to have fun dancing, not to admire how well the DJ strings together a series of songs on a special topic. 

Don't choose a tune primarily because it's unusual or weird, at the expense of it being an effective dance.  Don't get me wrong — weird music can be great when it's danceable, but the first priority is meeting the above requirements, motivating the dancers and having tempos perfect for their energy level.  If these are met then yes, obscure is fine, and weird is fun.

So the key word here is "primarily."  If tunes have a special theme and are wonderfully compelling to dance to, then there's no problem.  But too often a DJ's quest for special themes or lyrics leads them to dig up tunes with undanceable tempos and hard-to-hear beats.

All suggestions have exceptions.  Occasionally (rarely) the words will be important, like song lyrics about a father and his daughter, played for the father-daughter dance at a wedding.  But in general, lyrics aren't the reason to choose your dance music.