Starting Items:
Corruption potion provides a lot of sustain for Aurelion in lane replenishing mana, and HP from unfavorable trades.

Alternatively you may take Doran's Ring and 2 Health Potions for the mana regen and extra damage dealt to minions. However, I prefer the Corrupting pot for the sustain in lane since you are very susceptible to dying in lane from hard engages.

First back/Early items:
On your first back you want to purchase either a Blasting Want or Catalyst of Aeons since you want to build Rod of Ages as your first item.

Secondly you could purchase a Dark Seal however I only recommend it if you know that you have kill pressure in lane otherwise focus on building into your first item

Final item builds:
For every game you want to buy Rod of Ages first so that you can get the item stacks early on going into the mid to late game.

The next item varies between Ryali's, Zhonya's, and Banshee's.
When deciding you want to look at:
1. the team comps (How much AP, AD, CC, whether they scale or not)
2. what items your opponents are building
3. where you stand against your opponent (ahead, behind, even)

Typically if I am ahead of my opponent I would want to go Ryali's for the extra stats it provides and passive slow. But usually when going even or behind you want to look to building your first defensive item which is respective to your opponents team comp (Zhonya's vs. AD / Banshee's vs. AP).

Boots:
You want to purchase your Brown Boots before you finish your first item (typically your second back or after you purchase your First Back item).

When it comes to boot options it is similar to your second item buy.
If you're ahead then go Swiftness as it will give you the bonus movement speed for roams and slow resist. You could also go for Sorcerer's but only if you have a lead on your opponent, or if your team consists a lot of AP and you could use the magic penetration.

More obviously and my recommended boots would be either Ninja Tabs or Mercury Treds since more often then not you'll be going even with your opponent and it will give you the extra armor or magic resist.

Electrocute:

The keystone you choose is completely optional:
Cheap Shot will give you more dps and kill potential dealing extra damage to CC'd targets
Taste of Blood will give you more sustain in fights.

Eyeball collection can be changed out for ghost poro but I prefer eyeball collection

Relentless hunter can also be substituted for Ravenous hunter which is also optional

Conqueror:

Conqueror while isn't as strong on Auerlion Sol is still relatively viable as he has reliable damage output and kill potential which will help him in the later stages of the game.

Presence of Mind will give you the extra mana stacks on takedowns and will help him in the long run

Legend: Tenacity is also interchangeable (being the only one of 3 that Aurelion Sol can use effectively)

Coup de Grace can be swapped for Last Stand but it would very as to what champs your opponent plays.

Phase Rush:
Phase Rush is the rune I take into hard match ups for its slow and bonus movement speed. These match ups are typically melee since you can proc Phase Rush as more of a defensive tool.

Manaflow is what you would generally want to choose as against melee you can easily stack it with your abilities when they walk up to farm, and provides the extra needed mana.

Nullifying Orb can also be swapped in instead especially against high burst AP champions like Katarina

Transcendence will provide the additional 10% CDR and can also provide extra AP

Clarity could also be replaced with Transcendence since you want to look to roam if you're in an unfavorable match up

Waterwaliking again for roams providing bonus movement speed and AP, and helps in fights around the river

Scorch could also be subbed in but I believe Waterwalking is more reliable when taking Phase Rush

Inspiration:
For your secondary rune's you could splash any of the Precision, Domination, or Sorcery runes but I do prefer the Inspiration as a whole

Free Biscuits gives you more mana and health regen
Time Warp Tonic makes your Corruption potion and Biscuits instantaneous

Also adjust the bonus health with either armor or MR where needed

Ignite:
Ignite is an obvious choice on most midlaners, it helps secure kills

Cleanse:
Cleanse is more under used than I wished it removes the damage from ignite but it helps in surviving ganks and getting out of sticky situations since you lack a ton of mobility.

Exhaust:
Exhaust is best against your high burst champions like Katarina and can save you or a teammate from being solo killed

Aurelion Sol is relatively awkward to play with his Star Passive but once you get comfortable using his stars he becomes a lot easier to understand.

Use Aurelion's Q to both ganking side lanes and setting up ganks. Combining it with your E makes for a very powerful gap closer as it increases in size the longer it travels.

Because your Q has two parts to it you can also cancel it at melee range when getting jumped on by a target


As Aurelion's W is his main source of dps you would max it first, you want to get used to watching his stars rotation and you can recast it in order to hit closer targets.

You can use the first part of his W to farm the back wave and you can recast it to hit the melees. You want to practice moving with your orbs so that you can maximize and minimize the damage.

Yasuo's wind wall does not block his passive


Aurelion's E is what makes him as viable as he is having a half a lane sized Bard tunnel makes him very impact across the map.

Early on you can use your E to get back to lane as it acts as a pseudo teleport, so you can use it back to lane after backing either after an unfavorable trade or getting to lane faster.

When ganking you want to be wary of your opponents as your E will be cancelled if hit by any damage or CC. Your E can also be used to engage and disengage from fights.


Your ult is very powerful both in lane and in teamfights. The knock back at melee range help immensely when getting engaged on in teamfights. In lane this is also helpful similar to your Q cancel in disengaging from ganks or when getting jumped on.

Combos:

While Aurelion Sol is not the most combo heavy champion he does have a few

Q>W>Q Setting up ganks or trading


Use this to land your stun from a longer range, you want to let your Q grow as you move and then you use W to speed it up till it reaches your target where you recast it.

This can be used to set up ganks, chase targets, or tradeing as you can use your stars to hit your opponent as they're stunned

W>R>AA Disengaging targets

Use your R to disengage your opponents and hit them with your stars which can proc something like Electrocute.

R into a wall
This is practically a stun

W>Q>R>Q Chain CC

Cast Q then R to your star range then recast your Q to stun them and continue hitting them with your W. Since your ult is an AOE knock back you can hit multiple targets with this, and can help turn teamfights.

E>Q or Q>E THICC BOI

Cast your E and then quickcast your Q in front of you (this is because if your Q is a little bit off it could fly off to the side messing up the combo. Using this to get back into lane or ganking if timed and angled properly you will almost always get something out of it (blowing a flash or securing kills.

You could also cast your Q while walking and then cast your E to continue the star's movement but sometimes you may mess up the angle.