When I got to Tokyo the first shopping outing was to follow Corrie's directions (which she had previously posted on her own blog) and head straight to Kinokuniya in Shinjuku. More than fabric or trims, it was the inspiring craft books I wanted to stock up on.
It is an amazing store and I came away with a lovely collection (I only wish I'd had more time to explore the children's book section too).
What I did find also, was that the craft books seemed to be available in smaller bookstores as well.
I fell across this store in the very smart shopping complex, Tokyo Midtown, on the way back to our hotel. I ended up buying as many craft books from this tiny store as I had from Kinokuniya. And then I purchased a few more from Okadaya - ones that I hadn't seen at Kinokuniya.
Kinokuniya is the biggest and arguably the best, but you might just find in other stores a few books you haven't seen before or that have sold out elsewhere.