Hello,
this is my build to Vayne. I play her on top/bottom lane with partner. I mainly focus on dealing damage, because of much survivalibity from defensive runes, escape summoner spells that I take and her skills. With this build you will be nearly unkillable while destroying everybody, even tanks.

Why do I choose lane and not mid?
That really depends on enemy team, but by being on lane you have more chance in getting firstblood and more kills. Ganking from mid is not safe because after fight on mid you will be low on health, and afterwards you will have to get back again to lane instead of ganking. Actually I also found that Vayne ulti is perfect in destroying turrets, so after pushing one on top or bottom, you can stay and farm there or help in pushing other lanes. So you are actually 1-target killer with strong ability to push and eliminate enemy carry. That gives your team more chance to win.

Mid
You can also easily win mid, but you got to harass enemy and focus on ganks. This will let you to farm more and be ad carry.

Sorry for my language, but I'm still learning English.

The world is not always as civilized as people might think. There are still those who would follow the blackest paths of magic and become corrupted by the darker powers that flow through Runeterra. Shauna Vayne knows this fact well. As a young privileged girl in the heart of Demacia's elite, her father tried to convince her of the constabulary's ever-vigilant eye. Young and naive, she truly believed that her world was one of perfect safety, until one night, when a twisted witch took interest in her father. The malevolent woman overcame her father's conciliar guard, then tortured her family before murdering them. The young Shauna escaped only by hiding herself and then fleeing once the hag had departed, plagued by the screams of her loved ones as she ran. A burning hatred was born in her that day, one that could never be denied.

Vayne was able to take care of herself using her father's money, and she began to train as soon as an instructor would have her as a student. By the time she was a fully grown woman, she had become a grim warrior. However, the fields of battle were not to be her home. Demacia needed a protector, one who hunted those lost to the darkness. Shauna used her family's contacts to become the first Night Hunter, and now her prowess is the stuff of legends. It is said that those who practice the black arts quake when they hear that the Night Hunter is on the prowl. Despite her crusade, Shauna has looked at the League of Legends in horror. There are champions who have clearly lost themselves to the blackest of magics, and who have been embraced within the League even though they should be put down for the safety of all. The time has come for the Night Hunter to execute her secret mission - to purge the League of Legends.

Not all shadows are to be feared. At least, if Vayne has her way.

PROS

Great damage output early game without attack damage items
Not using a lot of mana
True damage destroys even hard tanks
No one's gonna run away - great chaser
Good escape mechanism
Gives a lot of fun
Stealth

CONS

Very squishy, especially early game
Rely on 3hits to active true damage
Targeted first
Vulnerable to cc - stuns
Hard to position in teamfights
Not easy champion (for me it's also pro)
Hard to use Condemn

Basically all skills for Vayne work both defensive and offensive.

Vayne ruthlessly hunts evil-doers. She gains bonus Movement Speed when moving toward nearby enemy champions.

You gain more movement speed while rushing to enemy champions. Passive affect only champions that you can see and only when you face them.

Vayne tumbles, maneuvering to carefully place her next shot. She rolls toward the cursor and her next attack deals bonus damage.

Don't use it only for escaping. It's really great at harassing, activating your Sheen, chasing enemy champions and it gives you possibility to be invisible for few seconds after using your ultimate. Your main source of dmg. (beside autoattack)

Vayne tips her bolts with a rare metal, toxic to evil things. The third consecutive attack or ability against the same target deals a percentage of the target's maximum Health as bonus true damage. (Max damage vs. Monsters is capped)

Ability is toggled and blocked. You can use it to deal huge amount of dmg every 3hits. Proper combo works - autoattack - - autoattack.

Vayne draws a heavy crossbow from her back, and fires a huge bolt at her target, dealing damage and knocking them back. If they collide with terrain, they are impaled, dealing bonus damage and stunning them.

Really hard to use skill. Remember that it goes off after second or two and it's hard to use it correctly. I don't use it very often, only if I'm sure that the target will be stunned or thrown under my turret, etc. The funniest thing is that you can stop Malzahar or Warwick ultimate if you use it at exactly the same time.

Readying herself for an epic confrontation, Vayne gains increased Attack Damage, stealth during Tumble, and quadruple the bonus Movement Speed from Night Hunter.

It's very underrated ultimate and I saw a lot of Vaynes not even using it. I use my ultimate to:

start gank (gives you stealth for some time after using [icon=Tumble)),
go invisible in teamfight when focused and go back safely,
get faster movement speed to reach enemy and grant a kill,
just run away,
destroy enemy turret.

Notice that you can use it nearly whenever you have possibility because of low cooldown. Keep in mind sometimes it's better to save it for later when it comes to retreat.

This is going to be short chapter.

SUMMONER SPELLS
I won't write what are good summoner spells and what are bad ones, because we all know that supports take Clairvoyance and not everybody takes Rally or Smite.

I used Flash and Ghost for more survivality which Vayne needs, but for better use of masteries i changed it to Exhaust and Ghost. This also allows you to chase and kill 1v1.

MASTERIES
For masteries I use 21-0-9 for more damage and experience. Nothing else to say.

Maybe if you want, you can try Ninja Tabi and 21-9-0 with dodge one masteries for more dodge after offensive Tumble move. But I haven't tested it out yet.

You have much freedom in choosing runes for Vayne. The most important is armor penetration and in my opinion - fortitude quints. Let's have a look.

Greater Mark of Desolation - armor penetration are the best one for Vayne.

- personally I prefer more health, because she is really squishy. As for some more damage I also take 1x Greater Quintessence of Desolation.

work well or - armor for more survivalibity. Choose those which suits you best. Attack speed ones are better.

& - I take some magic resist/lvl and attack speed here, but as I mentioned you can go fully in Attack speed seals and full magic resist/lvl glyphs. As I said you got much freedom here.

Vayne is really squishy, that's why I choose Doran's Shield first. You will be able to stay on lane for long time and still farm well. After I reach ~800g I go back and buy Boots and Sapphire Crystal. If I have some more money I also get Sight Ward and Health Potion.

I put ward in this bush, so I can still attack enemy champions when they want to juke my attacks.

I pick Sheen and then I start building Cloak and Dagger. After this I go for B. F. Sword to buy Infinity Edge after Phantom Dancer. So I pick Zeal after B. F. Sword, cause my attack speed deals a lot of true dmg. This is the time when you need damage and you go for Infinity Edge, as I said. Now you will shoot for 700dmg (crits). It's gonna hurt. If you want lifesteal take Stark's Fervor or...

You got to be careful cause they will focus you all the time. At the end of the game go for Guardian Angel.

Feel free to buy Elixir of Fortitude when you need it. This boosts your attack damage and health for only 250gold. Tip: it's better to buy Elixir of Fortitude than Elixir of Agility because of high attack speed from items and lack of ad before B. F. Sword.

Madred's Bloodrazor
I saw a lot of people buying Madred's. I dissuade buying it if enemy team doesn't consist from more than 1 high health champion. This item costs a lot and is worthless against squishies. Actually you shouldn't target tank at first, so it's not the best choice for you.

LIFESTEAL
Lategame, Vayne doesn't use a lot of shoots to kill, so she mostly rely on attack speed, true damage and attack damage. Buying Lifesteal isn't worthless for sure, but doesn't affect her much. Always when I'm close to death I use ultimate then Tumble, and I run away while stealth. I think that Lifesteal wouldn't keep me alive as that combination of skills. The item that worked well with Vayne for me and relied on lifesteal was Zeke's Harbinger.

FULL COMBO (with Silver Bolts)
autoattack - Tumble - autoattack - autoattack

EARLY HARASS
Tumble - autoattack - autoattack

GANK
Final Hour - Tumble - autoattack

CHASING
Final Hour - Tumble - autoattack - Tumble - autoattack

Please notice, that Tumble increase your damage and scales well with Sheen/ Trinity Force.

This guide is under ocnstruction, but I just wanted to show my build off, cause I didn't see anyone using the same. I will add more screens and pictures when I have some more time. Also I will focus on my language.

So... does it work? Got a lot of quadras first day of release with this build.
Thanks for all comments, I hope you like the build.