This post could also be called "well duh!"
A friend gave me some seed starting flats that have tiny cells in them, maybe 1/2" square or so, and there are probably close to 400 cells in the flat (I haven't counted them but there's a LOT) I filled them with soil and started trying to drop seeds on the soil and they were bouncing everywhere. Then a light bulb went off--I put an empty one over top of the one I was trying to seed, dropped a seed into each cell and voila! They fell right in the center of the soil-filled cell underneath.
I'm sure someone else has come up with this trick, or one better, but it sure made seeding the flat of broccoli raab much easier for me!