Believe it or not, all the substances that those “famous singers” are known for are actually really bad for their voices (among other things).... So here are some tips to get the most out of your voice.
REST Be sure to get your rest. If you are tired, your voice will be tired. A tired instrument will not allow you to produce your best possible sound. So get as much rest as you can.
RE-HYDRATION Drink room temperature water as often as you can to keep your voice hydrated. If you only have cold or hot water available, swish it around in your mouth for a moment. This action will keep your voice from being startled or stressed by different temperatures. Also Coffee and tea will dry your voice out, so drink in moderation.
RE-THINK Quit smoking. Quit talking too loud. Quit talking too much. If you must drink Alcohol drink it in moderation. Never sing if it hurts to swallow, or your throat hurts, you will just do MORE damage. Know when to cancel a gig. If a drummers arm fell off, you wouldn't expect him to play (unless he was the dude from Def Leppard)
RELIEF For those of you that have suffering with a cold or fatigued voice, my advice is you is NOT to sing.
However, if you have no option, below are some GREAT helpers to get you through a performance. In fact I use these even if I feel fine, and it really relaxes my throat before a performance.