Before any singing gig, whether it is an audition or a performance at a venue, there are some things you should do and some things you should avoid to make sure you put forth a stellar performance.
1. Eat Light & Right
It is best to sing on an as close to an empty stomach as you can tolerate. You don't want to be so hungry that your stomach is growling, however you don't want excess food in the stomach either. Any contents in the stomach will restrict the diaphragm and can cause you to sing out of key.
If you must eat, try to choose light options. Foods like steak will stay with you for a while, impeding diaphragmatic performance. Fatty foods like French Fries and other fried greasy foods can trigger phlegm production. On the other hand foods like soup, salad, vegetables, chicken, almonds and apples are great choices that digest quickly and don't increase phlegm production. Make sure to complete your meal at least one hour before your performance.
2. Choose the Right Drink
Don't Drink Dairy
Fatty products like dairy, chocolate and bananas cause excess phlegm. You can consume them, but try to cut yourself off at least half an hour before any performance.
If you do accidentally consume these products too soon before your performance, make sure to have a chaser of water or hot tea to wash down any gunk that might rise up on you.
Don't Drink Diuretics
Any drink with caffeine in it is a diuretic, which will dehydrate the vocal chords.
Coffee, some teas, energy drinks, and sodas will dehydrate the vocal chords if they contain caffeine.
Alcohol dries out the vocal chords as well and should be avoided before and during your performance.
Ensure you stop drinking these drinks at least one hour before singing, and follow them up with a big glass of water.
Drink Juices in Moderation
Natural juices can be beneficial to singing when consumed in moderation. The acids in fresh cut lemons, limes and oranges can help clear and coat your throat when added to hot teas.
While a squirt in some tea is ok, try not to drink juices to excess as the sugars and acids can become too much for your vocal chords.
Drink Water & Teas
Water is the best option for singing, there is no better substitute. Next best is the tea family, including green tea, oolong, and decaffeinated pekoe.
Hot tea is a good option that can help clear phlegm from the throat, but be careful not to drink it while it's scalding hot. A twist of lemon or lime can help clear fats like milk from the throat.
Contrary to some popular opinions, honey won't do much for you other than to sweeten your tea. You can get benefit from honey, but this is by drinking a shot of it straight, not by diluting it in tea.
Avoid Extremely Cold or Hot Drinks
No matter what you drink make sure it is close to room temperature or warmer. Drinking cold beverages will shock your vocal chords and make them tense up.
Hot teas are good so long as they aren't scalding hot, as you don't want to burn your vocal chords any more than you want to burn the tip of your tongue.
3. Warm Up Even When You Can't Vocalize
You may not always be able to warm up out loud depending on where you are performing. For instance a lot of cattle-call type auditions for TV shows and other performances may restrict you from vocalizing to reduce noise levels.
You could be backstage at a performance where the sound is so loud that you can't hear yourself warm up. In any case that you can't warm up using your normal exercises, try these following two techniques.
Expand Your Diaphragm
Start by sniffing four times quickly and deeply, then follow this up with a deep sip of air. When you sip air, pretend you are drinking air, in the same method you drink soda through a straw.
Repeat this a few times, giving yourself at least a ten-second break in between each sniff/sip interval so that you don't make yourself dizzy.
Even the lightest humming can get your chords warmed up and lubricated. Prepare ahead of time by memorizing your favorite scales so you can hum them whenever you need a quick warm up.
4. Avoid Breathing Excessive Air Temperatures
Extremely cold air can wreak havoc on your vocal chords and throat even when lightly inhaled. Damp cool air can also affect the larynx and throat, causing soreness and increasing phlegm production.
Avoid breathing any cold and damp air the days leading up to your gig. Prepare for the cold by wearing scarves to keep your mouth covered, and avoid heavy open mouth breathing when in frigid temperatures.
If you get caught in the cold and feel any sort of soreness or irritation, try breathing steam to help hydrate and sooth. A cup of hot tea can work perfectly in a pinch, but if you can get into a hot shower to generate steam the effects will be even better.
Air conditioning can also affect the voice as much as winter weather can. If the venue that you will be performing at uses excessive air conditioning, ask the manager if they can raise the temperature a bit.
5. Avoid Smoky and Polluted Environments
Not all pollution can be avoided unfortunately, however you do want to try your best to avoid these following irritants.
Try to avoid performing in clubs that allow smoking when possible. More and more cities are passing laws that make it illegal to smoke in clubs, but until all cities ban it you may be faced with a performance in a smoky club.
If this is the case try to remain outside or any place where there is no smoke until your performance.
Dry Ice Machines
Avoid breathing in the vapor as it can be very drying to the throat.
Large cities like Los Angeles have bad air quality days and being outside exposed to the polluted air can take a toll on your vocal chords.
Additionally, hanging around tour buses and other running vehicles can also cause problems so if you must be exposed to these conditions try wearing a dust mask to lessen the amount of smog you breath in.
In this tutorial, I have given you a number of ideas and techniques, to ensure that every performance is the best it can be, by preparing properly with food and drink.