The variation on Ashe build isnt so big. I get the IE early to harass and it synergize well with her passive.
The Starks is great to have early , and with the IE and the boots it should be the core items.
The starks makes it also easier to gank if get help with other AD champs.
Then the next item is the item that negate some other champs tankiness. Here I get Black Clever, as it is a good allround weapon. Nowadays you meet a lot of High hp cahmps and more and more stack HP, so wise substitute should be Madreds Blood razor. If u dont have big problems
at gettng focused but the team have probs with the other teams Tanks and High HP champs, get
both and Ignore the bloodthirster.

This is a quite standard build. Some people like a phantom dancer in there and it is really good substitute. I usually exchange the Bloodthirster or the Black clever when i meet very Quick champs that I need a little more movement speed.
The key item that can be replaced is often the bloodthirster depending on the situation.