No you do not need any skill to charm items. But you need charms and items that can be charmed. Not all of the items can be charmed.
Embelish increases the value of the item you use it. The increase of the value depends I think from the value the item had in the first place. If I am wrong in that please someone correct me.
tip : charms are very hard to find. And they are very expensive to buy. Try to insert them in items that worth it because once you use a charm you can never take it back.
You can have my absence of faith you can have my everything...
Tovi 
