i think that for productivity purposes even sound design should be a process apart, because when you're in the zone you can't really start making choices based on logic, your creativity is flowing and the moment you stop and say hmmmm should i eq this or how much decay this reverb should have or how much compression this needs you break your creative flow, so as long as your just putting stuff out of your head and into the daw i recommend its better to not worry about anything outside harmony, arrangement, rhythm, melody and all this stuff, you can change the kick later, you can change the snare later, you can change the pad later, you can add reverb and eq the lead later, but you can't put this idea you have in your head later, it depends on the person too but for me this works, once i have the parts of the song and the basic ideas down then i start to go over details and mixing stuff.
Cheers