Trading skins in LoL

Whenever I play with my friends, I carry with champion what i can play good. I've got S-, S or S+, but on this champ I've got the chest, so I don't get a chest now, but my friends get chests, because they plays random champions, what they owe. And they still get skins for my main champions and they don't know what to do with this shards. I'm very annoyed by this. So I think it will be good when we can trade or gave this skins between us. I think it's good and friendly idea. Thank you for answer. Edit: I didn't mean skins what you have paid, but skin shards from chests :) and only between friends

(Sorry for my english)