My mother gave me her dress dummy. Problem: it was size 10. NOT me.
I wound it with layers of batting from my scrap bin. Every layer stitched for stability.
Then I covered it with black cotton interlock fabric ( $12.99 at Textile Traders; the one with the furry, warm , inside).
Now I have a dummy that I can pin stuff onto in my own size. Starting with a freeform knitted and crocheted vest.