>>1484062For a lot of my vegetable seeds, I start them in paper towels, but I sow more seeds than I need. But if I start them in a tray, I usually put 2-3 seeds per cell and thin them out. If they're not literally in the same hole, sometimes I can pull out and transplant the extra seedling with minimal root damage. Otherwise, they get sacrificed.
For herbs, onions, and leafy greens, I just sprinkle them willy-nilly and thin them out later.