Things you might want to know when you play Vayne.You should get support which gives you speed so you can just take enemies down easily.Early game on Vayne is all about creeps,but if you get to late game and you are good Vayne you should get nearly free win.

Blade Of The Ruined King is must have item on Vayne,because it yells slow and mobility and that makes Vayne nearly impossible to kill Tumble and Condemn make your steps save and easy.
The Bloodthirster gives you much ATTACK DAMAGE and LIFESTEALthose two things make your laning way easier you must always get full hp from last hits and you are nearly impossible to poke out of lane your q yells you much DMG that you can kill enemies fast.
Last whisper You must build this if enemy builds armor so you can just penetrate their armors and kill em fast.
Phantom Dancer is also must have for Vayne to get envelope on silver bolts so you get movement speed+Attack speed to make every third attack count.
Guardian angel saves you once but not twice tip you must always remember if your team defends you and you can do dmg to carry em you have already won.It also yells Armor and Magic resists which are both useful.
Infinity Edge It makes your crits make too much DMG to handle it's also good purchase if you have got fed too early.

You should keep this on your mind.Also this Those are important spots to remember while playing vayne.