Directions Begin with about six inches of browns in the bottom of the compost bin. Add a layer of greens a few inches thick. Shovel some soil on top of the browns and greens. Finally, just add water until moist (like a wrung-out sponge). Maintain your compost bin by adding more greens, browns, and water, and mix the pile about once every two weeks to ensure air and water are equally distributed throughout the pile. You have just created a habitat for organisms like bacteria, pill bugs, and worms. These critters will digest your discards and create humus for you to use in your garden.