I love collecting scraps of fabric, as you probably already know from
my sketchbook. I've already hoarded a crazy amount. Don't even get me started on stores that will let me cut to my hearts content.
I have been known to take longer at a leather store than in a dressing room at Zara.
Sourcing is where I start to form color stories and ideas based on how the fabrics speak to me. Sometimes it's the other way around and I have the idea first before I begin the find the right fabric. Usually you find most basic fabrics on the store level, but the really special stuff -
the stuff that I dream about- needs to be ordered from suppliers. Those often have minimums that are incredibly high. (We're talking hundreds of square feet/yardage, sometimes a thousand).
Finding that balance between price and meeting minimums, you usually have to be a bit more creative. Maybe it's finding something in between or trying to develop the effect yourself. It definitely helps to think outside the box and sometimes DIYing just gives you better results.