Recently (okay, a year ago) she did a post on writing for comics:
That certainly rings a bell, I can tell you. I can tackle today's work knowing I'm in distinguished company.
"I try to carve my story up into roughly page-sized pieces. I will find out during the writing process (every darn time) that I've overestimated the content of each page and I'll have to simplify the story."
*You probably spotted that this is a tautology.
**And so is this.