I grow wheat grass indoors in winter as a green treat for my cats. :) If that's what you mean, I just use a couple small flats (I have/use plastic flats, but they're the size of peat flats... approx 4" x 6"). Otherwise, I use 4" pots or whatever is available...

I fill the pot with potting mix, tamp down lightly to firm the soil, scatter the seed heavily across the entire surface, cover lightly with additional potting mix, press down to ensure contact, water, and give it plenty of light (in a window or under grow lights). The seeds sprout quickly.... usually in just 2-3 days... then water as needed and the grass is full-grown in just a couple weeks. Cats love it. :)

I have also placed the entire pot in a plastic bag to retain moisture and speed the germination process, but I remove the bag once the grass is up a couple inches.