I've noticed that the planting instructions for a lot of seeds that require a bit of light to sprout will say either "surface sow" or "lightly cover." This is just a guess, because I've only grown scabiosa a couple of times, but with gerbera daisy seeds, you poke them about half the length of the seed into the soil. Kind of seems like they're designed to do that on their own, anyway! Other thing you could try is covering them lightly with fine gravel, like bird grit, to keep they from getting blown away.
