In starting of game you must take doran blade,after take boot but if enemy team has more mage take magic resist boot,then life steal is good,when you take the bloodthirster,you are good for fighting,you know ashe is carry so you must take phantom dancer for team,in fightinh you stay enough back,after if you have good kill you will take infinity,if enemy team have tank you will take madred's bloodrazor,if they have mage you will take maw of malmortius

Greater of Mark Desolation is necessary,take Greater of Alacrity. Greater Glyph of Shielding isnt necessary but if you want attack damage take Greater Glyph of Strength.