There you have it! Fill with soil, add your seeds and water. I use planter trays, lids , old baking sheets with gravel to set my pots on to transport them around.
First-I can't believe how much TP and paper towels we use (I just toss the flattened empties in a canvas tote-when the bag is full I take it to the garage and dump them in a rubber maid tote--and by no means do I get every single empty one from our house. If I get a shortage I just ask people to I know to save me some). Second-these aren't perfect . If they wobble a bit just kinda smush the bottom. (It is a technical term , haha) Third- I love I am recycling. They are biodegradable. And it is cheap cheap cheap!
For paper towel or saran wrap/ aluminum oil cores you will repeat the steps except instead of cutting in half you will cut the tube into 4"s.
Ready, set, seed.