Fashion is not only designed for adult. In the eighteenth century, children’s clothing experienced a continuing development from constricting garments patterned after worn by adults to apparel designed specifically for them.You don’t have to style them with high-class fashion, they wear clothes for 10 minutes before they grow out of them, you’ll get poor because of that.
I don’t think it’s wise to throw clothes away as trends are cyclical, and it won’t be long you’ll find you love something again, when the last time you looked at it you were tempted to threw it away. Saying that, if it’s old, smelly and tattered, do the right thing and bin it. There’s looking cool and mellow in slouchy clothing, but then there are just plain rags.