Place them in a seedtray tucked in damp compost, with the 'bowl' shape upwards. A very light sprinkle of compost over them will be enough - don't bury them! Keep them in a frost-free place, and watch for the buds to appear. Don't water from the top. Once they're on their way, you can pot them up.

I read somewhere that they can be placed in a small polyethene bag with some moist compost, and that when they have begun to sprout they can be removed. I am feeling doubtful this is true.

Hmmm...sounds a possibility, Jonathan, but I haven't tried it!