This is a little Ashe build that i developed after playing her for quite some time and i hope it will help you win some games. It mainly focuses towards attack speed at the beginning and then later focuses on walking through enemies in team fights.

The are some great runes that focus mainly on damage and speed(obviously). You could take out the quintessences of strength and add the 3.33% armor pen if you want to do a little better against tanks and heavy armor champions.

The masteries do the same as the runes, they focus mainly on damage with a little bit of extra gold capability because it will come in handy in early game.

These items are great for the speed and damage build but the one i would suggest playing around with is the Bloodrazor. I have also used the black cleaver when it comes to high armored enemies.
Also if you are willing to lose a bit of speed then you could always drop the boots and pick up something with more damage. The passive move speed on the phantom dancers is enough to get by.
You may also, if you have trouble staying behind creeps or teammates , want to build a health/resistance item. For health i recommend Warmong's and for resistance I suggest Guardian's Angel (because nothing is more annoying than an Ashe with two lives)

I personally like to use teleport as one of my spells but thats just me. For more survivability i suggest using Exhaust and Ghost, plus the way the talents are set up for this build it has both of them buffed.

Pro- This build is very good at getting the last hit on an enemy champion due to it's high attack speed.
Pro- End game this build will allow you to 1v1 almost anyone and, with practice, it works very well in 1v2s.
Con- early game, since you build phantom dancer first, it has very low damage. The runes and masteries will help you a bit but other champions will most likely do more damage than you early game.