I have the best edge and easiest mix in my voice in the morning, then on the afternoon I loose the edge and the mix often becomes forced. Even after a long warmup, I still don't find the same edge as in the morning. I don't talk a lot during the days, mostly working in front of a computer.
One thing I have noticed earlier was that while working in front of a computer, when I got tired/dry in my eyes my I would lean my head upwards to be able to keep my eyes a little bit more closed. This stretched position of my throat caused a tired voice.
Also swallowing and clearing my throat during the day seems to be a big no no.
Even though I follow these rules, my voice is still tired in the afternoon.. any more ideas?