Choose seeds that germinate quickly, such as bean or pea seeds. You will have almost instant gratification, as these seeds generally begin to visibly grow in as little as two days.
Glass jar with lid
Line the bottom of the jar with some cotton balls.
Spray them with a little water, enough for them to be damp, not soaking.
Place some seeds on the wet cotton balls.
Close the lid. Put the jar in a warm place.
Open the lid every day to make sure that the cotton balls are damp.
When your plants can reach the lid, remove the lid and place in a sunny area.