When singing, it is best to keep your hand below the grilled top of the microphone and to point it directly at your mouth while holding it about two inches away.  This avoids the vocal distortion that occurs when people sing too loudly into a microphone.  With the proper mic. control, your host can adjust the sound to help bring out the best qualities of your voice. 
     It’s also good to remember that when you sing softly, you may need to bring the mic. a little closer to your mouth but most importantly, when you hit a strong note or you are singing quite loudly, pull the mic. away from your mouth so you can moderate your volume. 

Yelling or screaming into the microphone is unpleasant.  Not only is it bad for the equipment, but it can actually be painful for the audience.  Likewise, swearing or using obscene language will not be tolerated.  The show is designed for the enjoyment of all ages and not everyone appreciates the subtleties of foul language. 

Applauding for each vocalist is a nice way of saying, “Thank you.”  In some cases it may mean, “Thank you for that wonderful song.” or “Thank you for singing so well.” or even “Thank you for stopping because you’re really quite horrible.”  Regardless of the intention, everyone appreciates a round of applause.  Booing is unacceptable. 

Tipping the Karaoke host is, of course, at your discretion.  However, if you have found the host to be entertaining, engaging, talented, funny, or even a bit nuts, it’s nice to let him/her know it with a tip.  The hosts will also do their best to sing songs that are requested by you.  Tips are especially appreciated when the host has connected with you personally by either singing a song you request or otherwise accommodating you.  The host usually has a tip jar (or hat) available. 

Additionally, it is extremely impolite to get up and begin singing on stage with a vocalist unless they invite you to join them.  This is especially true if you think they aren’t performing a song well and you decide to go “help” them.  Put yourself in their position:  If you were singing a song that might have significance to you and someone else decided to get up and “help” you sing it.  Would you not be offended?  It’s like booing.  It will also effect your position in the Rotation because it will be counted as a turn.
     It is also very rude to walk in front of a vocalist while they’re performing.  In some rooms, the setup is very tight or in others it may be the setup is in a place people usually walk through.  It is better to walk around behind a performer than to upstage them by walking right in front of them whenever possible.  It’s also impolite to get in between their monitor TV and their line of sight, for obvious reasons.