Keep your eyes open when you pay a visit in a flea market. There are plenty of items you can use with dolls. For example baby clothes have small enough patterns for making clothes. This dress is made by cutting a piece of an young girl's dress by sewing a tube from it with a seam only in the back in the middle. Really quick and easy.
There are also jewelry suitable for dolls. The doll on the left has a human necklace around her neck. The other one has two human ear rings, one around her neck, another in her hand.