I use quite a few index cards as well. I recently outlined an ebook I'm writing, a card to each section. I'll use them to physically map out the flow of product

I use quite a few index cards as well. I recently outlined an ebook I'm writing, a card to each section. I'll use them to physically map out the flow of products as well - use a card for each feature/ button and move them around. I also use them to make drawings, some of which I saved and published in a zine.