Add the pasta according to the packets directions or recipe if you have made your own. Finally add the corn flour if you want to thicken it slightly. Mix the corn flour with a litle water first. Using corn flour thickens but doesn't turn the stock to pastel shades of it's colour, it just makes it translucent and keeps the origional colour better. There are plenty of pasta shapes for soups.
Some shops sell pasta in the shape of characters especially for children.
You can add allsorts to this, like red cabbage. This gives a lovely red colour. You can also add cayenne pepper or chili pepper to give it a tang. The variety is endless, use your imagination. This is just the basic recipe.