Write down the seed varieties on your seed stakes and set them aside. Fill the seed starting tray with the seed starting potting soil. Tap the tray down gently a couple times to help the soil settle. Water it thoroughly until the water starts coming out the bottom of the tray, then pause and wait for a minute, and repeat twice more. The soil should now be very damp

Read the sowing instructions on the seed packet to determine how deep the seed should be sowed into the soil. Strawberry seeds, for example, should just be scattered on the surface of the soil, then topped with a very thin sprinkling of soil. Beans, on the other hand, should be sown about 1-inch deep.

Once the seeds are sown, insert the seed stakes into the assigned container so you can keep track of which seeds are which. Water thoroughly once more. It is very important, however, that you water with a thin gentle stream of water, because trying to water light soil like seed starting mixes with a strong stream can actually splash and dislodge the soil and seed, damaging the germination process.

Place the seedling heat mat inside the domed propagator, and then place the seedling trays on top. Place the domed propagator in front of a south-facing window in your home and plug in the heat mat.

Water about once a day, increasing the frequency if it is hot. The trays will drain water out the bottom each time you water them, it's okay if there's a little bit of water in the bottom of the propogator since it will keep it nice and steamy in there, but make sure there's not a bunch of standing water, (like more than 1 cm), since that can cause rot issues with the seeds.

Keep in mind the germination time for the seeds you are sowing before giving up on them and tossing the soil in the compost. Different types of plants germinate (sprout) at different lengths of time, and some varieties, like peppers, can take several weeks to germinate.