1) My starting item that I start with is Doran's Shield
I don't like starting with Doran's Blade to help me last hit because his passive handles that for me. So it's either between Boots + 3 Pots or Shield , which one should I go for and why?

2) What masteries should I get? 21/0/9 or 21/9/0
The movespeed in utility can help me keep up with people while using my E
But the 30 HP and HP per level in Defense can help me get some early/mid game defense.

I also don't know what to take in 21 Offense , I don't build that much Crit on Corki , so I shouldn't take the 10% increase in crit damage ( I'm taking it now because I don't know what to use the points on) What mastery setup should I use and what should I get in 21 Offense?

3) My runes are :

Marks - ArmPen
Seals - Armor (I run Manamune , DONT COMMENT ON THIS PLEASE!!)
Glyphs - Flat MR
Quints - 2 Flat HP and 1 Flat AD

The most problem I have is with my Quints , should I get all 3 HP Quints? All 3 AD Quints?
Please explain your decision on which Quint setup I should go for.

I would love for you all to help me , thanks !

Bump

1. Starting with Boots is better.Gives you more lane sustain with the pots and early MS which helps a ton,especially if the other AD Carry went ahead and bought boots as well.
Also Shield doesn't really benefit you very much after the early laning phase.

2. http://thefwcentral.com/lol/#&trees=0-3-0-2-4-0-1-0-1-0-3-0-3-0-3-0-1-0-1-3-0-4-0-0-1-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0
I would rather get the increased health in the Defensive tree then go into Utility.
If you are using summoner spells that are affected by Masteries then grab them and forget another tier 1 one.

3. All 3 Flat AD Quints is very helpful on AD Carries.If you have them I would also swap out Flat MR for Scaling MR,but that's just my preference.

I just started with Corki and have been using boots (even though I mainly play Dominion) + pots. I also went heavy offensive mastery with a defensive mastery secondary (zero points in utility tree) for the MR/Armor/HPs. I think for Quints I use two AD and one HP but 3 AD is good and even some speed boost wouldn't be horrible (especially if you get the 2% from utility tree).

I have been getting Zeal first after boots for the speed bonus and then buying Sheen. Sheen + spamming his ult is sweet damage! I also really like the gatling gun for assaulting turrets being guarded.

Corki is BA.

Bump

I main corki and these are all personal preference.
If u play normal and go mid i would recommend Boots
if u play ranked and go bot i would recommend shield
IDK about MR glyphs though

PS DON'T GO MANAMUNE ITS FOR NOOBS (its funny cause u said not to comment and i said in caps)

Manamune + Tri force actually works, it allows you to spam your spells for poke, and manamune is one of the most cost-efficient AD items barring a fully stacked Bloodthirster. My build generally goes:

Start with boots+ 3 pots

Buy ToG

Buy 2 doran's blades, or rush manamune (buy manamune anyways)

Get Tri force, starting with sheen, going to zeal, and getting phage last.

Buy a B.F. sword

Get Banshee's

Finish Infinity Edge.

Last slot depends, I'm actually not sure whether I should go for Phantom dancer, Black cleaver, or Bloodthister.

If you have any comments please tell me, just bought corki yesterday.