This is a very easy way to start some seedlings. Just find two plastic cups, one of which must be clear to allow light through. The plastic cups will cost you less than $3 or could even be free if you collect them after a family gathering or party. If you are re-purposing the cups make sure they are clean. Fill the bottom cup with a seed starting mix and water. Put your seeds in the cup and cover the seeds with an appropriate depth of soil then add a little bit more water. Don't add to much water - we don't want the seeds to rot. Cover with a clear cup and tape the sides.
Once seedlings have sprouted you can take the tops off. When the seedlings have grown their first set of true leaves you can transplant the plants to individual pots. You can grow a lot of seedlings in a very small space with this method. Make sure there is a light source around for the plants to use once they are germinated. Some plants need light to germinate so for them don't cover them with soil or if you do do so lightly!
The plastic cups are like terrariums that keep the moisture inside for the seeds to use.
You can reuse the plastic cups over and over again just make sure you clean them between uses to prevent disease contamination from different batches of seedlings. Seed starting doesn't have to use fancy equipment, just think outside of the propagation box! What containers have you used for seed starting?