In the begining of the game, be very agressive, rush people and try to stay between them and their minions, this will give you an edge when you fight. Also, don't be afraid to flash across turrets or run through them. The first kill is crucial for her. Use your condemn at the oponents side and always try to pin them to a wall for the stun and extra damage, if your a high level, you will pretty much have a guarenteed kill. Always go from lane to lane and fight, don't stick in your own lane, Vayne is one of the best gankers in the game. with this build you can 3 shot most champions with low hp. also, armor isn't a big deal due to the fact that every third attack does a percent of true damage equal to their max health. vayne is very easy to play but is very, very dependant on items, be sure to get those last hits and farm as much as possible. later game is when you want to farm for the last few levels and get money, first bloods and ganking will get you to the money you need early in the game. be sure to gank when possible, but don't leave your own lane open to attack while you are gone. lane with a champion that can hold their own against 2 opponents for a short ammount fo time while you gank.