I rarely have such finds in an actual fabric shop these days ( with the exception of the fabric I found in John Lewis at Christmas, I still have some left!) but I do sometimes find items I can use in charity shops the only trouble is you have to work around what you have. I can't just decide on a style first because when you deconstruct clothes you often have weird shaped bits left.
Anyhow I didn't find any wow fabric on garments but I did find two lovely T-shirts for a pound each, and what is even better about this is that I was looking at a T-shirt in a shop a few days before exactly the same as one them in style (different colour) in River island and it was nine pounds. Now nine pounds isn't bad I know but it was either a washed out pink or black, pale pink doesn't suit me and I have enough black. The charity shop one is purple, perfect! The other T-shirt is way too big but that's not a problem.