I prepared the bed for winter greens by just “raking in” some home-made compost. Nothing fancy. I also sprinkled the soil (before planting) with water to be sure it was moist. I used seeds I’d saved from last spring. They are tiny seeds so they need to be planted near the surface of the soil. The “rule of thumb” is the amount of dirt to cover the seeds should be equal to the size of the seed. When planting tiny seeds must either put dirt though a sieve or do it the lazy way, like I do, and sprinkle a bit of potting soil over them. Covering the soil with torn up Amazon shipping boxes keeps seeds moist until sprouting.