You can make paper pots out of newspaper for your seedling starters. After plant has started growing, you can plant the entire pot into the ground, reducing the disturbance to the plant and its roots. The pot will biodegrade in the ground. Paper pot makers like that shown in the video can be purchased from various vendors, including gardening suppliers and Amazon for around $15-$30.

With the six packs you buy from the store, you have to dig out the plant. It's kind of a pain.  With a paper pot, you don't have to do that.  Just prepare your garden soil, make a hole for it, and put the paper pot with the seedling it in at the same level this level as the soil; not not usually below, so if it's at the same level when you plant it in the ground. Be sure you remove the top paper so it's not sticking up.