You can't add your own graphics, this would require alot more programming than what is already involved. And WoW uses templates to make it easier for the programmers @ Blizz. A template is a basic design for something ie items, weapons, etc That why you notice that swords often have different names but look exactly like each other. Hell alot of the PvP weapons are like that, all they did was change the names of them lol. Basically you wouldn't be "making" your own stuff. You would just be modifying the current item with a new entryid and new name and probably new stats.
Now My question is, is it possible to make your own sets? I was thinking about making a Hylian set for Hunters on my server. Something probably like +2 increase int. by 35 +4 increase range ATK by 45. But I have a feeling I'll be forced to use the same itemsets already in use, but is there a way to modify them. Any Help would be much appreciated. Thanks
but can take a while if u do it for first time 
