Zed is a great AD champ however, during his early game he is squishy and so its best to level up your q and safe most champs slowly working them down. Even if it is to secure a few minion kills then its worth as his energy comes back fairly quick anyway. His late game is great and its good to get creative with his shadow such as leaping through walls and barriers to gank or to escape. His shadow is a great escape tool and it has saved me plenty of times. He is rather depended on accurate q so he can be a bit tricky in tense fast paced situations. When using his ultimate its best to initiate and slow them with your e, the attack with q and then call your shadow again with w and do another attack of an e then q to secure a kill about 90% of fighting situations.