I normally use recycled clothes to make things for my dolls. The fabric is cheap and you usually get more than you need with it.
This is made from an ugly old suit someone gave me years ago. I've made and made things from that fabric. Funny enough it looks a lot better on dolls.
Monster High Ooak Witch Dress by faydreams, on Flickr
Made this from a man's shirt found at Goodwill.
1875 to 1880 French Vest Bodice by faydreams, on Flickr
Of course for tiny stripes children's tops are so much easier to find them to scale than any fabric store. Erin is posing in a pair of leggings made from some and a top (intended for my 27cm obitsu guy) made from baby clothes.
Handmade Leggins for 25 cm Obitsu by faydreams, on Flickr