To start off, I would like to say that Xin Zhao top is very strong considering majority of the people in soloqueue lack lane trading skills and can be easily outlaned early on.
You are a bruizer, and your main goal is to kill the carry or ap carry in fights or put fear in their hearts making sure they don't go wild. Proiriizing that you have to keep in mind, positioning is everything and you can't allow yourself to just dive into a team and die, make sure there is follow up if you are manning it up or your positioning is good enough for you not to die.
In lane you do pretty much he same thing, except for the fact that usually you will fight another tanky dps.
For runes I run what I run for the most of solotop champs, 15 Flat Attack damage (Marks and Quints) - Allows you to trade well by doing quite a bit AA damage and being able to last hit well. 12 Flat Magic Resist Blues (most tops have some magical damage as spells and brawling with junglers will be easier if you have some initial MR, plus at times you don't know who you are facing toplane, if i am sure i am going agaisnt a riven for example and enemy jungler is lee i would take MR/level instead for instance but flat works just fine, not going to hurt. 13 Flat Armor Yellows (most people will AA you in lane and vast majority of tops are ad also creeps hit you at the same time making armor and essential thing).
Something like this:
Greater Mark of Attack Damage
Greater Quintessence of Attack Damage
Greater Glyph of Magic Resist
Greater Seal of Armor
9/21 Would be the masteries for most of the cases, taken offensive tree for Attack speed, Bonus stat from ignite and Armor penetration. 21 In defense leads to stronger lane phase and stability in fights (Tenacity, More Hp) Depending on who you are facing regulate the middle of the defensive tree from taking decrease on auto attacks landed on you (unyielding and block) armor or mr bonus and relentless. Defender works very well too, besides that perseverance is probably essential.
As starting items, cloth armor 5 pots is a choice vs heavy ad toplaners and auto attackers so you can win trades, flask 1 ward 1 pot vs hybrids and heavy jungler gank threats (wait in the fountain for the 2nd hp pot if you don't need to be present in the jungle.
First item you should be aiming for will be ther Blade of the Runed King that absolutely snowballs your way to victory if you get it at the right time in the right game or something less manly such as brutalizer. Blade of the Runed King (botrk) will allow you to focus carries quickly with amount of stat it god, sustain in lane well, kill heavy hp targets and do early objectives such as baron quickly.
As that being a prior offanensive item, stacking hp and survivability after it is what you aim for, warmogs is always a classic choice but locket of iron solari can really help your team out. Randuins Omen if enemy team is running heavy AA ad or just a heavy Ad team.
Last whisper if you are getting big and the are stacking armor (build black cleaver if you started brut).
Brutalizer into Black cleaver is the build you do when enemy team is not likely to stack hp but are armor heavy.
Ga is always a choice btw. (Dive town)
R > E > Q > W
For the most situations, E allows you to chase your lane opponent around and brawl on him more putting more pressure for longer time and faster, plus E scales wonderfully with its levels.
Also allows you to stick onto people in teamfights better.
R > Q > E > W
Prioritize Q when you are facing a heavy trader that is not likely to stack armor and hp (this is other thing why E is good, it deals magic dmg) but basically things like riven would force you into leveling Q to be able to answer the trade with equal threat.
Flash, Ignite for mobility and chance to kill things.
Quite simple, bonus gapcloser and ignite make you a threatening one.
As a toplane xin, you want to play aggressively to dominate your lane, however if you are on the wrong side and you are not going to get a jungler gank at ~3minutes, then that means that you are most likely to get ganked yourself at that particular time, meaning that being aggressive is not always good b/c initiating trades causes you to push the lane out and puts you under a threat of getting ganked, so unless you are sure that your jugnler will show up top as opponent's one does do not push and force the things, try to let your opponent push naturally and trade him when he trades you (you will win it anyways). If you started with an early ward and are sure that you are going to be able to safely get away from the 3-4 minute gank go for it, dominate toplane from very beginning by being aggressive when opponent goes to cs.
If you are winning toplane, try to take early tower and expand your dominance on redbuff/bluebuff in the jungler or put enemy mid into threat of geting dove on too, clear opponents jungle camps and in general be a man to fear. Keeping everyone on their toes does not only make you a baller but has a gameplay use to it, it is putting pressure of other lanes, if you are winning top, naturally enemy jungler will be pulled there with a magnite of whines and cries which is good because he is not going to be bottomside, make sure to aware your team when jungler is top.
Teamfights are not rocket science, you are required to be able to count and react.
If there is less people on enemy team then on yours (4v5 or you are able to catch someone off position) and no globals on people that are missing from the fight (not in a fog of war but in base or other lane) in general it is a good idea to engage a fight unless team is behind.
If you see an ugly looking ad carry somewhere aside from his team or dragging behind or being in the front, try to get on him at the time they would not expect you to, make sure they don't see you or just don't see you doing it, a good thing to have is a follow up stun/aoe anything that can prevent from enemy team from collapsing on you.
Xin Toplane is supposed to be big and if you can not 1v1 and ad carry you have had a tough lane phase or enemy ad is extremely fed.
Pros / Cons
* Good trade.
* Good engage/disengage.
* Does not do well unless dominating early on.
* Not that big of a mana pool.
* Requires a damage item to kill things.