Pros

Great at taking down towers
Pretty good ganks
Has lots of damage
Can be pretty tanky
Good initiations
ult very god in team fights
Pretty short cooldown on abilities (including ult)
Strong all game
Great with disrupting the enemies abilities with your knock up and cc

Cons

Can easily screw up ult
doesn't have much of an escape
Not that fast attack speed
Gets focused a lot since you are the initiator
Has to focus only one target to deal lots of damage

Xin Zhao can do tons of damage in seconds with his awesome combo while ganking!!!

When you gank, You initiate with your audacious charge. Then you click battle cry and Three talon Strike, dealing a massive amount of damage. If you an enemy is trying to stop you form getting your target, flash toward your target to gain distance, or use your crescent sweep to knock them back. You also could use your crescent sweep to deal damage to your target.

Right after reaching level 3, start ganking the lanes. I typically start ganking mid, but if another lane is feeding or is getting countered, you should gank there first.

If your team lanes aren't warded, you should ward it to make sure the enemy jungler doesn't get the advantage to gank the lane and potentially get fed (Which is never good).

If the enemy junler is fed, try to level up faster than him by farming more creeps since xin can be very quick at clearing out the creeps. Make sure to always gank the lanes though.

If a certain lane is warded, make sure to buy fast boots and ask that champ to buy pink wards. If he won't, either buy some yourself, or flash in through another way and audacious charge into the enemy.

Xin is pretty squishy and doesn't deal as much damage early game. Try not to invade the enemy jungle unless you have help, or you see a low health enemy jungler and you 100% positive that you can kill him. Try to the enemy jungle to see if you can kill them, or take their buffs when not there.

During a team fight, try to initiate and focus the squishier or fed champs when they are away form their team or you can audacious charge them.

When you do initiate into the enemy team, ult when they are all around you to scatter them away from each other and making them very vulnerable for your team to take advantage.

If there is a Katarina ult or a Mster yi healing, try to ult or knock up them in order to stop them, so you can kill them and stop them from inflicting tons of damage to you and your teammates.