I love the salt-shaker idea!
Sometimes I do the same thing with an empty pill bottle. I drill a small hole in the cap. Sometimes I add white sand so I can tell where I have or haven't shaken.
Then I use a 2-liter Coke bottle filled with vermiculite to cover the seeds.
I have a plunger-gadget and a dial-an-opening hockey-puck-shaped gadget.
I haven't yet bought the suction-and-needle puffer gadget, but I have one blunt-end needle that I might glue onto a turkey-baster-bulb.
The best thing I've seen for "put exactly ONE seed EXACTLY where you want it is from Lee Valley Tools. Precisely-sized indentations in thick plastic, like a mini-micro one-seed-scoop/
http://www.leevalley.com/en/ga...
Someone said that he used a pencil sharpened to a point, then dipped in water, to pick up one seed at a time.
I've used a tiny plastic or stainless steel measuring spoon to scoop one medium-size seed out of an ice-cube tray where I've been soaking them in dilute hydrogen peroxide.
Sometimes I use a small spoon or the plunger-gadget to drop 3-10 seeds onto a dry white saucer. Then I roll them aorund until one is well-separated from the others. I touch a finger to that ONE seed and pick it up, then rub two fingertips together until it drops into roughly the rigt place.
Sorry: no photos!