Hello, and welcome to my guide :D This is my first mobafire guide, so it maybe isn't that good. And i don't speak english regurarly so it may be abit bad...
But here starts my guide, so i hope you like it :)
Thanks to Jhoijhoi for learning me how to create a guide :D

Runes. I take greater seal of replenishment cause i often get mana issues early and mid game. I take greater mark of desolation cause it gives me some armor penetration that early game ignores almost all resistance! I take Greater Seal of Scaling Magic Resist so that i have abit magic resist against spell casters :)
Other runes i find usefull are: Greater Mark of Attack Speed Greater Seal of Armor or Greater Glyph of Cooldown Reduction

I take 21/9/0 masteries, with Durability and Veteran's Scars in defense. I like these masteries cause they give you alot of damage, and if you take Atma's Impaler , you also get attack damage from the hp.

The normal build is what i usually get, but the testing build, seems also to be very good. If you ask why i get Trinity Force simple answer, your tumble does 150% extra damage ! You get unstoppable. And i always Atma's Impaler or Banshee's Veil depending on the enemy team. If the enemy team has about more than 110 armor average, then you should get an Last Whisper instead of Black Cleaver

I take Tumble first, cause it gives you free harras, and enables you to tumble the way you like. When you tumble your next attack will deal extra damage. If you get Trinity Force, this damage is muliplied by 2.5 which is awesome ! That is why i max Q first. Do note that vayne tumbles the way your cursor is, making her great for 1v1 or duking. Silver Bolts second cause it deals true damage every third attack. It also
is an great anti tank ability, cause it does more damage more max hp the target has.
I max Condemn last. Make sure you use your Condemn, so that your enemy will hit the wall and get stunned in 1.5 seconds. Condemn also aplies a tick on silver bolts, so use it right after an basic attack. A great combo with vayne is: Basic attack, Tumble, attack, Condemn to trigger silver bolts as fast as possible.

I take Heal and Flash as summoner spells. Heal is just awesome to have, cause it can save your ***, if you turret dive. And flash is awesome to catch up to opponents, or to escape. even after the nerf, i still love flash.
Exhaust i find usefull to. Ghost can be usefull but i don't usually take it. Ignite.... i find it usefull in some situations but i usually don't take it. Like the other spells better.

Thanks for reading, and please rate this guide :D