Soraka is an easy support to pick up, while still being very usefull due to how much she is able to heal through teamfights and her ability to zone enemies away with her Starcall and Equinox

Time to explain my selection of runes!

Ultimate Hunter

VS

Ingenious Hunter

When running Ultimate Hunter on Soraka, I mainly believe it is to be able to use your Wish more flexibly without worrying too much about the CD.

Ingenious Hunter is intead meant to be combined with Moonstone Renewer, as these two combined make Soraka able to heal an insane ammount. But it still works with other mythics, as it'd reduce the CD of Shurelya's Battlesong and Locket of the Iron Solari

-OR-

Spellthief's Edge > POKING You should be looking to start with this in matchups in which you can easily poke the enemy botlaners, or when you should be playing more agressive in lane. RELIC SHIELD > SAFETY If, instead the matchup is not good, as in you'll be poked alot or they're bot is very agressive, you should opt for Relic Shield, as its bonus stats are HEALTH and HEALTH REGENERATION, which may be the decisive stats that let you survive the lane!

Moonstone Renewer Moonstone Renewer is very good on Soraka, as it increases how much you heal, and allows you to heal multiple allies at once!. The cons of this item is that it only provides benefits to your team. You as Soraka dont get anything from purchasing this mythic, so make sure you can survive teamfights before buying this item.

Locket of the Iron Solari Locket of the Iron Solari is a great option when the enemy team is diving your backlane like crazy, as its active gives you and allies nearby a shield, but does not augment your healing.

Shurelya's Battlesong I personally like this mythic the most, as it provide you and your allies with movement speed, while also passively giving you Ability Haste!. This item will also increase your survivability and will allow you to get better engages and disengages!

Redemption Redemption will always be a fantastic item on Soraka, as it increases your healing by ALOT, and the active lets you heal yourself after teamfights, after which you'll usually be on low health due to the healing cost of Astral Infusion

Ardent Censer This item works very good on allies who want to auto attack often, and hit hard while doing so. Do note that if your ADC is not someone who wants the atack speed too much (Such as Jhin or Draven), you should consider going for other items.

Staff of Flowing Water Staff of flowing water is no where as good as it was before, but its still okay Buy this if your team can do good use of the AP and Ability Haste this item gives to allies you heal. Remember that it also gives YOU these stats!

Mikael's Blessing Mikael's Blessing is a very situational item. Unless the enemy team is heavy on both AP and CC (such as Morgana, Amumu) Or has very dangerous but short cc (such as Lux or Varus) Consider this item!. <<Important>> Mikael's only removes stuns, roots, taunts, fears, silences and slows, it is NOT a full cleanse

Vigilant Wardstone This item should only be bough itf you really need the extra vision. Very good against champions such as Evelynn, Twitch, Fiddlesticks or anyone who has a Camouflage

Warmog's Armor This should generally be a build rounder, (4th or 5th Item), as the stats and passive works really good on Soraka as it allows her to have extra survivability in fights and after them

Chemtech Putrifier Chemtech Putrifier is a very good item when dealing with champions thet heal too much such as Darius or The Darkin Scythe: Rhaast. Buying this item also allows your teammates to have an extra item slot that they'd otherwise use on Griveous Wounds Items.

Zhonya's Hourglass Zhonya's Hourglass is a good item to have on your mind whenever you choose against building Locket of the Iron Solari, as its active may give your team enough time to respond to any enemy who's diving you!

Mejai's Soulstealer Mejai's Soulstealer Should really only be a last item (After stacking a Dark Seal, As it is meh at most on soraka. The free AP and Movement speed sure is good, but having a stacked Mejai's Soulstealer may make your enemies more keen on taking you down.

Early game your objective should be mostly to survive without losing too hard lane. If you feel you can do this sucessfully, then you can start thinking about being agressive.

On most matchups you will not have the chance to be agressive, but on the few you can , be really agressive, as Soraka's q Starcall deals a hefty ammount of damage early game. In this part of the game you should always be looking for a good Q Starcall before casting Astral Infusion, as the health cost can leave you very weak to an all in in lane. This is UNLESS your adc has much less health than you.

If instead its a hard matchup or they are getting help from teammates often, just ask your adc not to push so you can have the safety of your tower, since thanks to your E Equinox and healing capabilities, you're not quite easy to towerdive if you're with a teammate.

When getting into mid - late game, you should be looking to stay with whoever can get you asists while keeping you alive (Most of the time adcs fulfill this role).
As an example, while someone like Draven, Jhin, Orianna, Lux, Xerath can net you some nice asists without putting you at risk are good allies to stay with, someone like Zed, Akali, Sett or Kha'Zix are harder teammates to stand with at this point of the game, as they usually dive into the enemy team to get kills, leaving you open.

Whenever a teamfight occurs you want to stay in the backline healing your allies in this order of priorities: CARRYS > PEEL > FRONTLANE > OTHERS
While you are meant to stay in the back, you can move foward in case someone on your team overextends (Such as a Vayne diving into the enemy team) But it should only be done if you know your teammates can have your back, as a dead Soraka doesnt heal as much as an alive one.

This guide is still a WIP, but i'll release as I manage to make progress on it!

Good luck on your games and remember to have fun!