hi, i do pretty much the same as fiona!
i always use glass to weight my body just 1 bag in the centre surrounded by fibre fill and baby fat in the bum
also i put fibrefilling in the shoulder and top of the leg then make a little hole in the centre and add a few pollypellets
then add a little more fibre filling so you can't feel the pollypellets inside the shoulder of the body
hope this helps