A stash is also built by going to thrift and consignment shops. Sometimes sewers downsize by donating to or selling through these shops. And then there are yard sales to grow your collection of fabric. And please do not forget the ready-mades available through those shops.
I confess I like using quilting and quilting techniques in conjunction with garment construction (see the latest "threads" magazine #160, "Sophisticated Deconstruction" for example ). Garment construction means buttons and zippers, etc. Thrifts and consignment shops are great for this too. And then I've bought garments that didn't fit me or anyone I knew; but, they had great sewing ideas enshrined in them. I keep them in my "sample garments" box. A soda and a quiet time makes going my SG box a real pleasure.
May I quit confessing?
Happily, Another Enabler