Hi folks,

Here's my experience.

Things to NOT do:
1) Do not drink coffee
2) Do not drink beer
3) Do not drink hard alcohol
4) Do not take aspirin
All the above strip the vocal chords.

Things you can do:
1) Drink Gatorade or juices to keep your blood sugar up, replace electrolytes so that your energy is up. Good energy, better voice. DON'T drink grapefruit juice! Ariel Rogers (I didn't recognise her at the time) gave that to me before my first main stage at Summerfolk years ago and I wanted to curse her (cramps).
I often drink Coca-Cola when I can't get juice (oops . . . well...Cola of some sort. Coca-cola is being boycotted because some of their plant workers in South America who have been trying to organise unions have been shot by death squads to prevent unionization). Ginger Ale is better.
2) A "temporary" fixer upper if your voice is indeed rough - Drambuie, Irish Mist. The thickness coats your vocal chords. The solution is only temporary though.
3) Do "mouth" exercises. Open your mouth all the way and stick out your tongue as far as it can go several times. Do a minute or two of "rolling R's" with your tongue. Do a minute of "brrrrrr" using your lips
4) Do a few minutes of arpeggios using your voice. La-la-la-la (actually sing out "Eee-eee-eee" rather than "la-la" from the lowest and then up the scale to hit the highest you can possibly reach. Do the scales from as low as you can go to as high as you can go;
5) Sing using your diaghram rather than falsetto (except to reach those unreachable notes)

Extras:
You may want to consider this technique. Singing at home and practicing is different than being on stage or in a studio with an actual microphone in front of you. If you have a sound system, or even just a microphone, set it up and practice singing into the mic. The microphone is what ends up taking all your focus when performing and it can be intimidating. Learn in the process your "relationship" to the mic.

Finally, the more you practice and sing the stronger the voice gets.

For music that never noices (and hopefully a voice that never die),

Len Wallace