Sona is so much fun to play.

Whilst she is squishy and has a lot of cooldown and mana problems early game, she is poke heavy and her passive can chunk enemy ADCs for a decent amount of health. Her sustain in lane is excellent and her E and ultimate give your team a real edge in terms of CC and movement speed.

Her Qs are world renowned for stealing kills and this is no lie - it is hours of fun yoinking kills away in team fights.
Her W lets you become the health potion.
Her E lets you kite like a god late game and you can outrun a fair amount of speedy bois with it.
Her R is just dumb as hell and I love it - make those suckers dance for their lives in the middle of a teamfight - the CC is a perfect addition to her kit.

I prefer to play her with the tiniest hint of utility, hence Ardent Censer and Unholy Grail, but also with a solid amount of AP for that sweet sweet scaling. Late game AP Sona is a force to be reckoned with for sure, on top of generally just being fun to play!

Overall, Sona is a really sturdy pick if you play her right and can win even the toughest matchups - she is by far my favourite champ to play in the support role purely for her high sustain and fast movement speed, whilst also not being too mechanically difficult and only having one skill shot.

Is this the best build you could do? No! Am I a pro? No way. But this is a build I use lots and is tons of fun to play! Feel free to experiment and mix and match with other stuff to find what suits you and your play style.

This guide will go over:
Runes and Items
Sona's Passive
Laning
Late Game and Teamfights

AP Sona Runes:

Summon Aery

Summon Aery and Sona go great together. It makes her poke much more effective and increases her shields on allies. Aery shields allies for 35-80 based on level (+25% AP).

Manaflow Band

Manaflow Band gives you up to 250 mana, granting 25 mana every time you hit an enemy champion with an ability. This, again, works amazingly well with Sona, as you use a lot of mana early game due to Aria of Perseverance . Poking with a Q therefore grants extra mana - so it's basically just free mana, it would be kinda dumb not to take it!

Transcendence

This gives you 10% CDR - which Sona is going to need for her high cooldowns in the early game. Also, it turns extra CDR into AP in the late game, making you eat those kills for breakfast.

Gathering Storm

Gathering Storm gives you that juicy juicy extra AP. Every 10 minutes, you gain more adaptive damage. I like to take this rather than Scorch as it allows me to take support items like Unholy Grail and Ardent Censer whilst still maintaining high levels of AP, allowing Sona to have some utility whilst also doing damage >:). A healthy balance if you will.

Biscuit Delivery

Biscuit Delivery is very useful as it restores 10% of missing mana and health for 15 second and increases your mana cap by 50, with 3 biscuits in total, 1 every 2 minutes. This rune is good on Sona due to her early mana problems and gives her even more sustain as she doesn't have to recall to get some mana back in the very early game. It also heals, so you can focus on using your W on your ADC rather than for healing yourself.

Cosmic Insight

Cosmic Insight grants tons of CDR - again, really useful for Sona's high cooldowns!

Summoner Spells:

Flash

Flash is easy. It's a key spell for pretty much every champion. On Sona, you can use it to engage with an R for that montage play or as an escape.

Exhaust

Exhaust is great with Sona imo. It slows the enemy down by 30% and reduces their damage. Paired with Tempo, it will slow the enemy down by a whole bunch and make it much easier to kill them quickly!

Alternatively: Ignite

Ignite does true damage for 5 seconds and applies grievous wounds, so it's good against supports that do a lot of healing like Soraka or Yuumi . Personally I prefer Exhaust, but choose what works best for you and your matchup.

AP Sona Items:

Spellthief's Edge is a standard item on Sona. It provides good AP to help her early game poke.

Ardent Censer is the most important item to build on Sona. Make it a priority. It only grants 60 AP, but it increases heals and shields by 10% alongside 50% base mana regen, and 10% CDR.

Athene's Unholy Grail is generally the item I build second. It, again, only has 30 AP, but has 100% base mana regen and 10% CDR, alongside unique passives to enhance healing and grant AP.

Boots: Ionian Boots of Lucidity is usually the only boots I build on Sona. Paired with her E , they make her super speedy, on top of giving extra CDR.

Then I tend to just pick whichever AP/Support items will suit the game. I prefer going Seraph's Embrace > Rabadon's > Lich Bane for AP, but it always depends on how you adapt to the current state of the map and what's happening.

Sona's passive is arguably one of the most important parts of playing her.

It does solid damage, whilst also providing damage reduction and slows. It is excellent for poke in the early game, in following up ganks, and in late game teamfights.

Sona's passive, Power Chord , is an empowered Auto Attack that occurs after you have used 3 abilities, with different effects depending on which ability was last used. Because of this, it's important to be aware of how many abilities you have used and you should think briefly ahead to estimate which ability will be most effective in your situation, then use the right ability to trigger that.

If your Q, Hymn of Valor , was the last ability used, your Power Chord will be Staccato; this deals 28-336 (based on level) (+28% AP) total magic damage. This is super useful in the laning phase for poke (and also great for KS cough cough).

If your W, Aria of Perseverance , was the last ability used, your Power Chord will be Diminuendo, reducing its target's size and damage output by 25% (+4% per 100 AP) for 3 seconds. This is useful against enemy ADCs and other high damage champions, especially in the late game. I aim to use this in teamfights paired with Qs to help teammates.

If your E, Song of Celerity , was the last ability used, your Power Chord will be Tempo, which slows its target by 40% (+4% per 100 AP) for 2 seconds. This is useful in chase situations and against high mobility champs. It's a bog standard slow really, just use your common sense.

Using the Power Chords to your advantage can be the reason your team wins lanes or teamfights - it gives Sona a busted amount of poke that makes her very difficult to lane against. Her Power Chords and Qs make her a real bully and will have you winning trades in no time.

The laning phase with Sona is easy: the aim is to poke.

Sona's range is huge, so you can poke enemy champs from a large distance with your Q .
You'll want to land as many hits on the enemy laners as possible without getting greedy, using a Q in combination with your Power Chord to do maximum damage - so you really need to pay attention to when your passive is up and use it effectively.

In the very early game, you want to aim to use your W sparingly as it is very mana heavy.
Only use it when your ADC is getting low and doesn't have health potions as casting spells on allies will refund some of the mana cost. Don't use it to heal yourself! That's why you have 2 health potions and biscuits - unless you've exhausted all of these options, don't use W purely to heal yourself.

The key here is to watch your positioning - stick with your ADC and stay behind your minions as often as you can to avoid taking damage. Ideally, you'll want to recall after your support item upgrades and buy the first couple of parts to Ardent Censer as soon as you can. I'd go for mana regen first if you can't afford both for more poke in lane.

Don't forget to buy control wards and switch to Oracle Lens once you have completed your gold quest. Warding with Sona is very easy as you can move quickly with your E to get wards in key places. Wards in the river and at drake are important in the early game, but if an opportunity arises to place a deep ward then by all means take it.

Roaming early game with Sona for ganks isn't really all that fun because of how squishy she is, so the focus should ideally be on getting gold for AP items, poking the enemy laners, and getting good vision on the botside river and jungle to set up good ganks, all while popping the W occasionally to keep the old ADC happy and healed up.

At this point you should ideally have a lot of AP, good mana regen, and low cooldowns - this is where the fun begins.

Whilst the focus is less on poke and more on healing, that doesn't mean you can't hit a load of Qs and Power Chords for some solid damage whenever your heal is on cooldown.

The aim in late game teamfights is to land an R on as many people as you can, with a focus on enemies going for the all in and high mobility assassins to allow your team to counter effectively - a huge advantage over the fight.
Power Chords are definitely going to do the most damage in these situations, but also remember to use the right chords for the right target - Staccato for magic damage against squishies, Diminuendo against high damage dealers, and Tempo for slows.
*cough* Be careful not to kill steal *cough* (but ripping a Q in a teamfight with someone low health will probably finish him off. Ez clap, eat those kills like the true support main you are. And if you get pinged for it - the mute button exists for a reason B) - if you're winning massively and want to **** around: KS with an R. It is funny as ****.)

Vision wise, the priority should be around objectives. Drake and Baron should pretty much always be warded and cleared of enemy wards whenever they're close to coming up - but make sure you aren't taking too big of a risk. Be aware of where the rest of your team is and how your game is going and make decisions accordingly. Map awareness is always key, but especially so when in the late game as a squishy support!

Finally: as silly as it sounds, stay calm! Mute your teammates if they're being mean! The goal here should be to have fun, even if you're losing your game. You'll play better with a positive mindset and a rational thought process.

<3 enjoy your league games and have fun playing Sona! <3