Simple Build for Vayne, Start with getting boots of speed or dagger, and a stack of 1 to 3 pots dependent on item you decide to start with. once you hit enough money, Back for boots, then move into getting items to make zeal, a dagger or brawlers gloves or both. After you get zeal focus on working to get to phantom Dancer.If you have to buy the agility cloak and dagger first, then do so.

Stark's Fervor is next, but if the situation calls for it, you can go to Black cleaver instead. if you work on cleaver I'd suggest getting dagger first for the extra AS then the Bastard sword. With Stark's I'd suggest getting the Recurve Bow first, then the emblem of valor and then the Stark's. After getting both Black cleaver and Stark's I suggest getting Infinity Edge, and then the Bloodthirster.

Situation Items I would suggest, would be Wit's end, Cloak and Dagger, and Banshee's Veil.

A replacement Item for the build is of course The Trinity Force, it works well for her, but it is a very expensive item to get, nothing wrong with that, but with the many other items that she will want, it can get rather costly, and I've seen many Vayne's get laid to waist simply because they were working on getting Trinity Force.

This is a build only, and a simple suggest for items, runes, and skill selection and the path to take to get to them, you don't like the item set up, great tell me why.