Pillow cases are good; enough air passes through the cloth for them to breathe. Storage containers of an appropriate size so the snake is neither totally cramped nor rattling around in a big container are also good. When you evaluate whether the snake is too cramped, remember how tight they like their hides to be. You'll need to make holes in the storage container.
For either one, make sure it is tightly closed so the snakes can't escape. Use separate containers for each snake. And make sure while you are transporting them that the temps stay within an appropriate range.
But, why transport the snakes? Can your mom and little brothers come to where you are? That would be much less stressful for the snakes.