Sure, if you just sew the sleeves and collar shut! Creativitydo not have any pillow cases that my mum is thinking of throwing away though. Will tshirts do?
For my smaller bags and wristlets, wallets, etc, I use the little drawstring bags that you can get from sephora if you have your stuff gift wrapped. They're perfect and since I regularly order from sephora.com, I always choose the free gift wrap option so I get all these neat little drawstring bags. They're also perfectly sized for pouches. I don't have any larger bags without dustbags but the pillowcase thing sounds good