(Please don't be harsh, first guide)

To make things simple I will say, practice practice practice. Zed is really difficult to use, and before you play a full on game with him, play with bots. He takes a while to get used to, but it's worth it.

Pros
- Great on 1v1 ganks
- Mobility
- Lots of damage fast

Cons
- Difficult
- Won't do well in team fights

You want to single out targets, If you see someone alone pushing top lane, or wherever they may be, try and take them. You will do twice as much damage with your living shadow, so don't be afraid to jump right in and take them.

With Zed, you have increase melee range and abilities. Use your living Shadow to attack people hiding under turrets without harming yourself.
When tryng to escape, use living shadow ahead of you, teleport to it, then use your e, this will slow your enemy. When you use combos like this, you show you know what you are doing, and can make up even more creative ways to use Zed. A great way to confuse people is to, when running away, place your living shadow in some brush, keep running, and then switch with it. You can also place it across jungle walls, like flash.

You want to get lots of attack damage when using Zed. Increases basic attacks and your abilities. When combined with cooldown reduction, you can use living shadow way more often, giving you a better chance of survival.