Most of what you read and hear out there, are myths.
The absolute best thing for your voice, is rest and lots of water. Not hot or cold water. Room temperature is best, so as not to damage your vocal cords.
To get through gigs, I have cheated. With a shot of Sothern Comfort sipped a little at a time. But warm tea with honey and lemon, etc... They actually have adverse effects on your vocal cords. As I said, I have done them in emergency to get through a gig, but you are actually damaging your vocal cords, and you get through the night, but pay a price, which is why you will usually find your voice worse off before the end of the night.
It is best, say before a gig or recording session, to get lots of rest, and drink lots of water, maybe even a 1/4 to a 1/2 gallon, a few hours before the session. This gives the water time to hydrate your vocal cords.
And yes, pot is really bad for your vocal cords.
A little trick for warming up, that I learned from my mom, who is a world class vocal instructor:
If you have had a sore throat, rather than singing to warm up, you can hum. Do it so that it vibrates your lips alot, and that is about the right spot. It still warms up your vocal cords, but is less stressful on it.
Also, one thing actor's don't usually take for granted, but vocalists do, is the muscles in your face. When you sing, like an actor you are likely using emotion, which means facial expressions. Actors use face excercises that work out their lips and tongue and eyes and cheeks, everything. I have found this to be very beneficial before a gig as well, for singers. Contort your face in all kinds of shapes, stretch those muscles out, and you will find it will set you up that much better for singing as well.
Try it out.
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