I've tested this character constantly, this is a shoot and run type, great at getting rid of minions fast, doesn't kill enemies well till around 14 (alone) but can push them down to low health making them run back. - with others you just run in and basically steal the last few shots on the enemy. (not a kill stealer - just gets enemies dead when they try to run). This is a good beginning Ashe build - run fast, hits fast, crits alot. basically gorilla warfare.

*Do not use frost shots on minions - remeber to turn it off when not shooting champions.*

The runes haven't been tested at all (since I am not level 30) - but on paper it seems to work really well.
The masteries has been mostly tested - 8 offence and 6 utility so far and works great even not a full power.
Items fully tested, get the phantom dancer really fast if played right.

Also Last 3 items on the list can be changed to any item that seems necessary needed at the end... if you can get triforce - power to you.

Kill minions mostly, but try to include enemies in volley shots, once level 7 start farming out of the jungle when not pushing the enemies back off your turrets, the Fortify spell helps keep them off while you do this. Quick revivals are for beginning of game for any accidental deaths, so you are back in the game farming away, and also great towards the end if you get killed - they never expect to see you again so fast and get shot to death quickly before they can run.

Its a good class for people just beginning to play, doesn't let them die cause they can run out of any situation, though there is that occasional stun that gets you. They shoot minions down fast and slow down enemies to let the allies gank them, or if the enemy is 50% left can kill them with crystal shot and just shooting crits.