Start with a food grade seedling tray. Make sure you add drainage holes if your does not have them already.
Get yourself some decent potting soil and add a half inch of soil to the plant tray.
Sow your seeds! Choose your seeds and cover the surface of the soil. Fast growing seeds ideas: turnips, radishes, broccoli, cauliflower, lettuce, spinach, arugula, amaranth, cabbage, beets, parsley and basil.
Give those seeds a good drenching. Mist the seeds and the soil using plain tap water in a spray bottle. The key word here is mist. Do not water them directly from the kitchen faucet or a watering can. Doing so will disturb and redistribute the seeds, risking washing them straight out of the seedling tray. After spraying the seeds and soil, gently pack down the seeds against the soil using an empty tray.
To complete planting, pop that same empty tray upside down over the top like a dome. This will prevent light from reaching the seeds. Doing so will stimulate seed germination. Do not use clear plastic lids, as this will defeat the purpose. Keep the tray covered until the seeds have germinated and grown 1-2 inches. This may take approximately 3-5 days. Do not forget to keep the soil moist by removing the cover and giving it a good misting of water several times a day.
Once the seedlings reach 1-2 inches in height, remove the cover and leave it off. Don't panic! The micrograms will look very pale, and that's normal! Once you give them some light, they will turn from light or dark green or red to a darker color. The light will also help those little greens to grow quickly, plump up and form a thick mat. You will know when it's harvest time when your microgreens have grown two little leaves on top.
It's harvest time! You will need a pair of scissors and a container to collect your crop. Just grab a bunch of greens in one hand and use the other hand to snip off the plants just above the soil line. Harvest when you are ready to munch on these yummy microgreens because these little plants have a short shelf life. Once you’ve reaped what you have sown, toss the soil in the compost bin and begin again.