I've been playing Ashe a bit lately (think I finally found my hero too! ECA on a fleeing <300 hp enemy is full of lulz) and I go with this build:
V and FA till both are maxed
PB after V is maxed
ECA when I can
I group with the same guy, so having V and a good FA helps us get kills early on. That, and like I said, I love to shoot ECA on an enemy who thinks he's gotten away :P I get all my early kills like that
My item build is:
Meki -> Chalice first off, I like the mana regen, and I fire Volley like a madman (I use clarity too, I'm a huge mana *****)
Boots -> Boots of swiftness. These boots save my life. I can run to an enemy, set him up for a gank with my friend, or I can get away from almost anybody (Save for people like Kassadin)
B.F. sword if i've got kills/Pickaxe if I don't -> infinity Edge. Crit rating, better crits, and damage, do i really need to justify that one? This thing is DELICIOUS!
recurve bow ->Last Whisper. By now i've got money flowing in, I can either afford the Recurve bow to turn into last whisper, or get LW itself
Depending on how the game goes, my last two items may vary.
Madred's Bloodrazor is my usual 5th choice, since I seem to always go up against tanks, and I love the attack speed it gives.
Wit's End if i'm fighting an all caster group.
A health item like Frozen Mallet, or something that gives me a nice health boost, since I'm squishy, and by this time, I'm getting into the fray a lot more.
My damage is pretty decent, late game is where I get most of my kills, setting up a Volley, auto-attack, Volley, ECA-when-they're-low combo that either hurts like a ***** or kills most heroes.
Granted, I usually sit with 9-0-5's or something like that, because I'm still relatively new, but I do better on this champion than any other champion. My one problem is aiming; I miss shots at point-blank range because I suck at aiming XD