太多粘液/痰气不顺畅，太少（口干）声音发涩，都不行。。。

warm lemonade really effective in clearing up throate quickly...

if you want to hydrate the voal fold quickly, two large cups of warm water very quickly

and keep on drinking while recording

no 瓜子，no spicy food， no smoking ...

no black tea 铁观音 type. green tea is ok. 

if singing high note, apple or a teaspoon of light ice cream to add mucus / lubricant to vocal cord ...

 

just my 2c