I use cardboard egg cartons to start my seeds. Each egg-shaped cup in the carton is the perfect size for an individual seed-starting pot. To try this: First, cut off the lid and use it as a tray to set the pots in. Next, moisten the seed-starting mix, fill the pots with the mix, and plant a few seeds per pot.
As the seeds sprout and begin to grow, cut the pots apart, thin the seedlings, and leave them in the tray under grow lights or in a sunny window until they’re ready to go outside. Keep them moist!