You must be carreful at early game because vayne is definetly late game hero.. You can have health problems at early game so play safely dont vaste your mana for harass; everyone thinks that vayne must be in mid but i dont think so, because if you have tanky/dps teammate with you you can attack from backside that you wouldnt lose hp, if you lose you will easy target for enemy..

You must use exhaust for late game because if enemy is high ad/dps you can be ambushed badly, you have low defance so using exhaust for moments like that is great idea.., exhaust reduices %70 of enemys damage.. Ghost for catching enemy much more easly you know,Vayne have good passive but base moviement speed is vorse.. You can buy flash instead ghost.. Enjoy it please! :)

Play premade! If you re not skilled enough dont ever try to play ranked alone..

Pros:
♥ Damage burst! At late game you will able to kill everyone including tanks easy and quick!
♥ Your Tumbles cooldown is 1.5 second with your ultimate it makes you invible so use it all time when able!
Cons:
♥ Worse defance at early game! You must stay safe til you get your phantom dancer..
♥ Slow champ! Bad for defancing lanes at early game..
♥ Hard gameplaying at early game.. You need to be skilled.. :)

Offense offense! Best defance for vayne is offence!

If you play premade with tanky/dps friend it could be easy to win games.. :)