This Ashe guide is meant to serve as a guide for an Ashe with a lane partner. If you are midding or soloing then switch ignite for teleport. This ashe is extremely squishy early game but after the Infinity Edge the life steal from masteries and the Doran's Blade keep her alive. Late game this Ashe will have no contest in any 1v1 the life steal and attack speed will always keep her alive.

When coming back into a lane after being dead or going "B" always shoot volley and then 1 basic attack on an enemy champ for max damage. Always wait to use that passive crit unless you know for sure no enemy is around.

Only use frost shot when engaging an enemy champion otherwise it is a waste of mana.

Try and grab Blue Buff early on so you can spam volley.

If you do what #1 says in mid or solo top then you will be able to harass the enemy champ extremely will and shut down their farm.

Dont be afraid to use your ult to initiate mid or solo top. Most players dont expect an early ult in lane from ashe so use volley to harass then pop your ult then volley again and secure the kill with frost shot.

The armour penetration early game really makes up for how little attack damage ashe has in the beginning. After the last whisper there is very little the enemy team can do with 36 armour pen plus 46% of whatever is left.
The mana regen is simple, ashe depends on her volley "W" to do damage before her phantom dancer so she has to be able to spam it. Thats where these come in.
The cooldowns are just an all around good thing to have on any champ. On Ashe they all her ult to come into play every team fight rather than every other.

Start with a dorans blade for the life steal and damage. Starting with boots and pots it a poor decision because ashe has no health, damage or life steal in the start so you need to get some. Next go back for bots of speed and a BF Sword if you can. Get the BF Sword before the Berserker's Greaves because the extra damage is extremely useful early game. Finish the BF with an Infinity Edge to make full use of her crit passive. Then grab a zeal for the move and attack speed but leave it at that until after last whisper or blood thirster. Next grab a last whisper or blood thirster depending on how the game is going. If you are having health problems grab the BT first then last whisper but if armour is the problem go for the LW first. Then finish the phantom dancer. the second BT and PD are for end game wreckage.