Instructions
Go to yard sales and scour the tables and boxes of old dishes. Look at all the cups and saucers. If really old ones have a trademark, get it.
Check the flea markets, Goodwill and any other secondhand stores.
Go online and check eBay and other online auctions. They have tons of antiques and dishes.
Stop and check antique shops. Sometimes you will find a wonderful cup and saucer hidden by itself.