I like glass beads the best. I can't hear the beads. I fill to 2/3 then stuff the rest with polyfill. In the body I fill 2 or 3 balls made of glass beads using a half of a knee high per piece. Depending on the doll I will stuff in poly fill and make a nest for the glass beads ball. Then I stuff more stuffing, then a scent wafer in the middle, then more stuffing, then another ball until I get to the top. Some dolls take 2 balls of glass beads and some take 3 balls of glass beads in the body. You could alternatively use 1 longer panty hose oblong ball of glass beads and a smaller one up top. It really depends on the shape of the doll. I do the same as Anne, weighing the front of the head and stuffing poly fiber fill in the doll. It should lean forward rather than backward to be properly weighted. I put a lot of fiberfill in the shoulders and neck to support the head when it's sitting up.
That way when the mommy holds it, it leans forward like a newborn does.