my build focuses on having ashe to drop down enemies and slow them for you or your team to kill end game shes almost impossible to kill if played right by staying behind your team and dropping enemies

using full attack speed runes benefits ashes ability to hold her distance with enemies with her frost shot, plus gives you a upper hand on people early game being be to harass well

For masteries I focus on straight ad while putting points in summoner's wrath/resolve/insight to give you a choice of summoner spells

giving ashe boots of swiftness gives her great mobility and the ability to close in on enemies combined with her frost shot, then getting a phantom dancer helps ashe with her passive and gives her easier crits, the bf sword gives you some dmg to help while you finish the rest of our build with another phantom dancer for more crit, attack speed, and movement speed. I.E. will give yours crits more dmg to help later in the game, ending with bloodthirster and warmogs gives you survivability end game

Pros
good harass
good cc with her frost shot
great survivability late game

Cons
squishy early game
easily oom