Here's what it looks like

David
If this is your first try, if you have read this forum, used a light mix of soil, moist but not too wet and have the terrariums in bright light out of direct sunlight, then wait and see. You will most likely succeed with a lot of patience. It takes a while sometimes to see mouse ears.
If you have tried before and failed, then post about what you did then and the forum posters will give good advice and you will succeed.
I had never had any luck propagating leaves until I came to this forum and talked to all the good folks here. Now I have forests of new plants, little mouse ears everywhere!

Try different varieties too, some are easier to propagate then others. I have had great success just pinching off a leaf and sticking it back in the pot with the mother plant. A few months later I dig out the baby plant with a spoon.

Irina used to do that, so I have experimented. It does work!
It is quick and easy.