Daphne mezereum comes easily from seed. Look for seedlings growing around your bush, I am constantly weeding them out.

Perhaps so in Washinton, but here in Britain I would say that every garden centre/nursery/plant outlset sells Daphne mezureum. As Bulbaholic says, wait until the berries are red, watch out birds love them, then pick. Clean off the flesh, wear surgical gloves, the juice can be unpleasant to the skin and is hard to remove. Sow the pip straight away in ordinary seed compost. Cover with 1/2 inch of compost and put the seed pot somewhere safe from rodents, but exposed to the weather and wait for them to germinate (usually the following Spring). Either pot up immediately or wait until the baby shrubs are a bit bigger.

I don't even have to clean my own seeds, Owdboggy, the snails do that for me I just pick up the dry seeds from beneath the shrubs and pass them on to the seed exchanges.

If I leave the berries on the shrubs we get no seeds at all. the birds strip them off instantly, even before they are ripe sometimes.