Hi Camille. 

    I know where suppose to warmup before singing. But if we do warmups in the morning then if we sing later in the day do we need to warmup again or just warmup once a day? Also what's a good time to warmup? Cause I notice that in the morning my nose is too stuffy and too much phelm in my throat. And my throat is really dry. Is there away to get rid of morning throat dryness and the phelm? Thanks. 

Hi, Jenny! If you've warmed up earlier and are singing casually, you should be fine. But if you plan to work on challenging material, I'd suggest saving your warmup until right before your song work. 

Each singer is different, so pick the time of day that your voice feels best and you feel energized!

As for dryness and phlegm: sleep with a humidifier in your room, drink lots of water (all throughout the day), and consider doing a saline sinus rinse!