I take flat AD Marks and Quints, for a lot of early game damage, while Armor Seals help me to survive in early game and MR per level help me in late game.

With 21-9-0, I take every possible form of damage increase in offence, and reach down the defense tree towards Veteran's Scars, for increased health.

I start with Boots of Speed and 3 Health Potions, for increased ability to escape or chase enemies. I try to stay alive and dive my enemy only when I'm sure to kill him, so that i can buy B.F. Sword and Vampiric Scepter, to significantly increase my damage. I take Berserker's Greaves and The Bloodthrister for increased damage afterwards, and continue with Infinity Edge and Phantom Dancer, for increased crit chance and speed. I end with The Black Cleaver and Last Whisper, when my opponetnts start stacking serious armour.

Maxing Burst of Speed gives you the most damage potential, while Riposte maxed by Level 13 will still give you a lot of damage. Lunge is more like a gap closer, not a damaging ability. Of course take your ultimate whenever you can.

Exaust helps you to get away from gangs or to chase running enemies, and Ignite is helpful for killing low health opponents who are likely to get out.