Learning about perspective can be lots of fun because its so tangible. One of the few art classes I can remember is the one where we learned about perspective. Our teacher took us outside and has us stand at the corner of the school, right with our nose nearly touching the wall and look down the length of the building and see how it shrank in to the distance.
You can teach perspective in lots of ways. Put 2 balls of the same size on the table, one at one end and one at the other and look down the table at them both.
I showed my kids a Monet picture on the wall, "Poppies" and had them compare the size of the house to the size of the women in the foreground. I told them the house was smaller because it was further away. In real life the house is much much bigger than the women. It only looked small because in the picture We are further away from the house too.
Its pretty easy and fun craft for the kids. You can do this with just about any landscape. Have a Horizon with sea and sky or land and sky. Have different sized objects going from biggest to smallest pasted on. We used sailboats on the sea. We glued paper waves on to give it some depth. Color and cut out the object and paste it on the paper. I suggest glue sticks. Liquid is just so heavy. And messy. Very very messy. You can do trees in a field, or cars on a road. Whatever you want a picture of really. There are endless printables you can print out and color.
*remember to click on the links, lots of info for helping you in your craft making, and no I don't get anything out of it, just don't want you to miss out.