Hello, this is the first build/guide Ive ever written, I chose to put it here because I wanted to share my take on playing Ashe in the support role. Havent seen builds like this on her so I thought it may be interesting to some of you and encourage you to try it out.

I am a long time League player, playing it for fun mostly. Currently sitting in high Plat, aiming to reach Diamond this season.

Ive always loved Ashe and I feel she is currently struggling in her ADC role. That paired with me being a support main, I decided to try her out as a support, mainly because of the AP Imperial Mandate build. After playing that, I wasnt satisfied because she felt weak + was kinda useless later in the match. None the less I had fun with her poke playstyle and sniping people with ults so I decided I would try to experiment with different items. This led me to the build Im putting here, which might seem crazy but worked for me really well.

For me, picking Ashe as a support provides my team with great poke, map control with vision and a low CD engage/disengage.

This build is AD oriented, besides the Liandry's Torment. Going AD makes Ashe's W poke hurt more than the AP and it also makes her autoattacks matter in fights. The items I build on her are packed with tons of Haste which is even more emphasised with Liandry's Torment. This provides a lot of CDR allowing you to spam Volley and Enchanted Crystal Arrow very often. The Liandry's Torment burn adds more the poke and the AP stats boost Enchanted Crystal Arrow damage. Umbral Glaive combined with her Hawkshot makes Ashe really gold at providing and controling vision all over the map.

You should establish lane pressure since level 1 with your Volley + Arcane Comet + Scorch poke. Against non ranged supports, you could easily squeeze a few autoattacks in there too. If you are laning vs Thresh / Leona / Alistar, this is very important as it will force them to back off and use a potion. From there, they are pretty much denied going all in level 2 if you keep poking and keep distance.

Autoattacking whenever you can is important because before your 1st back (Tear) you will quickly run out of mana. Look to land Volley on both support and the ADC to maximise the mana/damage efficiency and wait for Arcane Comet to be back up before poking again (ofcourse depending on the lane, if needed poke them whenever Volley is off CD).

Ashe might struggle versus poke oriented enchanters like Karma before getting Tear of the Goddess, after that you should be able to outpoke her because she will run OOM quicker.

What I like about Ashe support is her ability to potentially stop a gank with her W slow (is harder tho with junglers like Hecarim and Udyr who can outspeed the slow).

When laning, look to use Hawkshot to reveal the position of their jungler or provide vision of objectives like Dragon/Scuttle/Herald. When shooting it through the jungle, aim diagonally to cover as much of their jungle as possible. Even if you dont reveal the enemy jungler, you know where he isnt so you can predict it.

After hitting 6, look to catch their support/ADC out of position and possibly kill them, or just straight up engage on them after poking them down. You can also use Enchanted Crystal Arrow to disengage their engage or a jungler ganking you.

Make sure your ADC understands you are poke reliant and tries to follow your poke to maximise the pressure. The worst scenario is ADC just farming and not keeping distcance, allowing your enemies to all in him.

Mid to late game your goal is PPP protocol - position, poke, pick. Try catching enemies off guard/out of position with Enchanted Crystal Arrow, securing a pick to get your team objective priority.
Establish vision control by clearing enemy wards with Umbral Glaive and Oracle Lens, shooting out Hawkshot to save your team from fatal facechecking unwarded areas or to provide vision of Drag/Baron.

In teamfights, use ult to engage on important targets or disengage unwanted fights, followed by poking with W and autoattacking when possible.

Avoid moving alone as you are an easy pick - squishy and immobile.

Ashe is IMO a really good support who can provide very good map control either by providing/clearing vision or setting up kills with Ult and W poke. This build works well for me and is supper fun/annoying to play against. Always be aware of your positioning and, most important, have fun playing the game!