I’ve been trying out using the clear plastic veggie containers (specifically the grape tomato box from Trader Joes and the tomatoes on the vine box from Costco) to start my seedlings.  They are shallow, and have holes at the bottoms already.  They have been working perfectly.  I’ve started seeds of the California Poppy, Cilantro, and Purslane so far.  CA Poppy is taking the lead!

California Poppy and Cilantro in reused plastic containers

Two TJ's and one Costco veggie container