When I mix/prepare my bom, I usually add handfuls of water to the dry feed little by little, rubbing it between my hands to moisten it, until I've reached the right consistency, which for me should be a bit dry rather than too moist. When I shape my bom, I will first wet my hands and feel out the bom when it's on the spring/weight. If it's too dry, I will just wet my hands again and 'plaster' it on the outside, till it's solid. This always works for me, I hardly ever throw the feed off, and when I did, it was coz somebody else prepared it. So in essence, I dont really pay attention to the ratios, 1:3 and so on, I feel it out and rub the scoop of dry mix until it feels right.