How many is too many?

I like to sow one seed per pot and 90% of the time I will do this. However with some flower seed I find this is impossible to do? Occasionally seeds are like dust, some self saved seeds can be difficult to separate from the chaff. So I will sow in trays/pots. Last year I used tweezers to single sow poppies

But theres always another variety of something I want to try.