Alright so this is a pretty standard build, very complex and easy to use for new people to the game. do not go mid with this build unless your confident in yourself

With the hard out attack damage runes, ashe seems to do a lot of damage, i tried this build out a couple of times and it worked.

Ok, most of your masteries will go into the offence just because ashe is a very offensive player.

Doran's Blade - Good for early game due to the lack of health ashe has at the start

Boots Of Swiftness - I find these to be pretty decent for ashe the speed gives her better opportunities to gank early game, remember this isnt a mid build you most likely want be laning with a Tank, or Stunner etc.

Infinity Edge - This is Ashes main item, you mostly like want to rush this even before boots. but if you can just get the BF Sword then finish your boots.

Phantom Dancer - Another item that is critical on ashe the movement speed boost it gives is amazing + Attack Speed and critical strike.

Wit's End - This is another good item, especially if the other team has AP carry's, you want this item to boost your attack speed more then it already is from phantom dancer.

Blood Thirster - Last but no least the blood thirster, if the game hasn't already finished then get this and go for some Ks's to get the stacks up on the item so you have lots of life steal.

Ghost/Exhaust - i believe this is the most common combo for your spells, ghost for it's movement speed and exhaust for the slow, kind of make Ashe unbeatable

Flash/Exhaust - Only get these if your going to play mid, the flash is very helpful if versing tanking ap's such as vladimer.

Pros:
Easy Build
Lots of Damage
Attack speed King
Kill Most people before close to you
Good Gold Farmer-Always aim for last hits

Cons:
Very Squishy
Quite hard ulti to aim loljks its op
Quite Slow without any items