Warming up is always important - this has grown into something really big, and there's a lot of competition. No sense for anyone not to try and do it at their best :) As for changing the voice, because there are almost 300 auditions now, I simply don't have the time to go on Skype and coach people - plus I don't want to show any favorites, necessarily. Something to keep in mind is that, in most runs, when Frisk looks into a mirror, it says "It's me" or "It's you", but during a pacifist run, there's one line that sticks out to me - "Despite everything, it's still you." Frisk gets a lot of temptation from a lot of sources, but never tries to be anything more than honest, and never wants more than to help everyone achieve their golden ending. So "trying" to be cute, or any emotion, comes across as fake (this is a common problem, don't worry :) ) It's hard to be genuine, but being real and in the moment will get you a lot farther in voice-over work than trying to play an emotion. Hope this helps!