Planting Seeds - What is "Seed-Starting Formula?"?

Go to your garden store and buy a couple bags of Pro-Mix. If
you're into large scale, you can buy it by the bale.

I start between 400-600 chile pepper and tomato plants in my
basement every year, and have been growing for 25 years now.

Depending on where you are, you may want to invest in a seedling
heating mat. Solanaceous plants, like chile peppers, tomatoes, etc.,
like a little bottom heat when they're first germinating.

Don't overwater the seeds after they're in, and even when they start
to sprout, keep the planting medium damp, but not soaked. Once
they throw their first set of true leaves, you can transplant them to
larger pots.

As suggested earlier, plant three seeds to each cell. You can always
cull out the weaker ones if all of them sprout.