My wife has been sewing for a number of years and has sold stuff here and there, mostly through friends and some word of mouth. Over the past few months, she's been putting more effort into the business. She started selling bags on consignment at an area yarn shop and has sold quite a few of them. She realizes, though, that she needs to expand her market.
There is a local business that runs an indoor (and in season outdoor) pop up shop every Saturday. For $20/day, you get a 9x9 space to sell your wares. It's not a flea market. It's mostly crafters: knit, crochet, soap, woodwork, flowers, jewelry, etc. So the people who come there to shop are the type who are looking for handmade items and understand that those sorts of things cost more than mass produced stuff at Walmart or Target.
The place does some marketing but also depends on each merchant doing their own advertising so we'll be blasting Facebook, Twitter, Instagram, etc. to try and drum up business.
We'll see how it goes. If it seems like a good market for her, they do the pop ups every Saturday so she can do it regularly if it's worth her time.