The first batch of seedlings has been re-potted. I made both plastic cup pots, and recycled newspaper pots. I am also watering the seedlings with a dilute fish emulsion fertilizer. They are a lovely deep green and have beautifully stocky stems.
The tomatoes can be potted up buried all the way to the cotyledons, or "seed leaves". New roots can grow from any point on the stem and this will create a deeper, stronger root system.