Hey all this is my second build please criticize, I want to get better.

Vayne is a very interesting champion. She has 2 escape abilities that both are great in combat as well. She can destroy anyone, even someone who has a ton of armor. This is the way that I play Vayne.

5/17/11: After some more recent gameplay decided to change my build pretty majorly.
5/12/11: Build Published!

I use the common 21/0/9 build, allowing for major damage early game with steady damage later on.

I go with 9 Greater Mark of Desolation
9
9
3

These help her with armor penetration, attack speed, and plain attack damage all right away in the beginning of the game, helping you destroy your mid opponent.

Pros:

She can destroy anyone mid-late game easily
She can gank amazingly because she has a stun and added movement from her passive
She has escape skills that allow her to escape easily
No one can stand up to her in 1v1 combat
Can last hit minions with ease
Can zone out early game mid opponents

Cons:

Little health
Can be CC'ed out of a battle
Teams tend to target her because she is new and because of her amazing damage capabilities
Requires a lot of farming to complete this build

I go with Ghost and exhaust

These allow me to chase or escape extremely easily, or get to a team fight even faster.

The items I go with synergize with vayne really good. Sheen helps her deal massive amounts of damage pretty early in the game, and trinity force just adds to all that when it's finished. I am against most snowball items, but with vayne I always seem to get a lot of kills with little deaths, so i decided to help her survivability by getting the leviathan. Black cleaver and SOTD help her get some late game AS while black cleaver and the bloodthirster help her get some much needed AD and LS.

Early GameTry to go for mid. I know people may think that she is a better side laner, but she can completely zone out the other mid unless they are someone like fiddle who can just regen their health. When you are mid you want to be last hitting almost every single minion you can, while keeping the enemy mid out of exp range with your auto attacks. At level 1, three of your attacks plus your W's passive can take down most other champions health to about half! AT LEVEL 1! This is extremely Overpowered and should be exploited as much as possible. Once you hit level 3 you should be on the offensive looking for FB. You should try to pretend like you are going back to your base but then go along to the bushes on one side of your lane. Wait till they get close to your turret. Tumble up to them and knock them back towards your turret all the while auto attacking them. Tumble when it is up and you should have FB easily. Port back to base buy some shoes and if you have enough a pickaxe, otherwise just save your money. You should be buying elixers and wards to help give you an edge.

Mid Game
By now you should be level 11-12 and have a few kills. It's time to start ganking. Look for the lane that has the champs that have the lowest health and are the highest forward. Ping the map and say that you are ganking that lane. Go and hide in the bushes on the side until they inevitably go too far forward. Punish them. Activate your ult and tumble in using the invis to get behind them. Use condemn and push them towards your allies or into a wall. Congrats on an easy kill. If you can chase the other one and kill it, but port back to base and finish your boots of swiftness and get a B.F sword if you can.

Late Game
By now the other team should be cowering at any mention of the name Vayne. and several surrender attempts have failed. Finish your Black Cleaver and go hunting for some weaklings that are all alone. The drill is really easy, just tumble and auto attack till they are dead, and push the lane that they were just in. Easy money and another mental defeat for the enemy.
Not much you can really do but destroy the other team one by one until you're build is complete and you can pretty much go 1v4 or even 1v5.