Control ward - Place it whenever your ganking lane. If it spotted ward clear it and try to bait it for kill. Usually players will deward your control ward so try to wait where your control ward is for 10 seconds or less. They might Deward it or put another ward so try to jump them if they get closer to you.
Trinity Force - good for positioning yourself.Every time you hit the enemy tri force passive GIVES you MOVEMENT SPEED. So, try to position yourself where they are going. Example they are trying to run from you, position yourself in front of them. Once you knock them up you can position yourself easily.

Skirmisher's Blade - Good for 1v1
Stalker's Blade - Good for chasing high mobility champions.

CORE ITEMS
Skirmisher's Blade - will help you clear camps quicker and to land your Q knock up quicker.
Blade of the Ruined King(BORK) - good item for 1v1 enemy.
Trinity Force - good for positioning yourself.
Mobility boots - To be more active in lanes.

Low Damage(Tank) junglers are very easy to counter with Xin Zhao.
1. Do not let them farm or get level try to invade them in their own jungle camp but always look at your map because some players will try to help their jungler. So, if you see that the mid, top, or bot is missing just try to leave the area. It could be warded or they seen you on the map.