This guide exercises the components required to play a sustainable Mid lane Morgana. With a butt load of health for an APC and an exceptional amount of lifesteal, you can dominate the enemies with ease using a few neat tips and tricks that I have to offer! Morgana is a very versatile champion in the mid lane, she could make or break any game at any time. Which adds excitement to your gameplay!

I like to take 9 armour seals, to add a bit of survivability to counter any AD mid laners such as Talon in the early game.
9 Magic resist marks to counter the rest of the mid laners that do go AP instead of AD, keeping in mind these are only worth something within the first 10 minutes of a battle.
9 Glyphs of Flat Ability Power to add more damage to your abilities. The reason I did this is because the glyphs of AP have much more of an effect during the early game rather than going for magic penetration marks and MR glyphs. A bit off but I do find this works.
And finally, 3 quintessences of flat Ability Power to finish off the runes. As a default these should almost always be your Quints for every APC in the mid lane.

I like to go 21/0/9 for my masteries, giving loads of AP in the offensive tree, and some utility to help you out in the laning phase.
Take 4 points in Sorcery, because CDR is always great! - Effect: 5% CDR
Next, build 1 point in the Exposed Weakness branch, this helps with your Tormented Soil ability which should almost always be cast after Dark Binding! This adds a bit more damage which will be much more affective in the late game phase.
Take 3 points in Mental Force, to add loads of AP as you level up! - Effect: +0.89 AP per level
1 point in Arcane Mastery should help with your lack of AP in early game laning phase! - Effect: +6 AP
Executioner is great for dealing damage to the enemy that will already be low in your lane! Take 3 points in Executioner, how about it?
Archmage is an awesome way to scale massive amounts of AP in the late game! - Effect: +5% AP
Dangerous game is awesome when you are getting 5 man ganked and kill one of their nooblord team mates in a fight! - Effect: +5% missing HP and MP when you kill an enemy
Devastating Strikes is good for countering AD mids while still dishing tonnes of damage to them! - Effect: +6% Armor and Magic Penetration
Arcane Blade allows you to execute those purple minions for gold to spend on items to destroy your enemies with! - Effect: 5% of AP is dealt on auto attacks
And finally, Havock is great for dishing loads of damage to your enemies! - Effect: +3% damage
3 Points in Fleet of Foot will help you chase down those fleeing enemies! - Effect +1.5% Movespeed
1 Point in Phasewalker will allow you to recall quicker than your enemies can get you!
3 Points in Meditation will allow you to stay in lane longer without having to spend loads of gold on Mana Potions!
1 point in Strength of Spirit will help in the late game by giving you HP regeneration!
Last but not least, 1 point in Runic Affinity will allow you to Keep those buffs the enemy jungler gave you when he failed to gank your lane!

My first purchase is generally going to be a Dorans Ring or Boots of Speed. If you have an enemy like Morgana or Ezreal in the mid lane, make sure to get Boots of Speed to dodge all those pesky skill shots! If you are against an enemy that doesnt have skills that you can dodge, start with a Dorans Ring to destroy them before they get the chance!
The first item you should go for is a Rod of Ages. This gives you loads of HP and MP to help with your survivability. This should always be bought on Morgana.
Your second item should be your boots. Buy either Sorcerers Shoes or Boots of Mobility. If you are finding yourself roaming a lot, buy the Boots of Mobility for that extra boost that could save your allies!
Your third item choice should always be a Rylai's Crystal Scepter. This gives you an exceptional Ability Power Boost while granting you some decent health.
Just where you thought this build couldn't get any better, it has. Zhonya's Hourglass is your last core item and should be bought in all games, that is, if you hadn't already won. This item gives you loads of AP while granting you a great amount of armor at the same time!
Heavy AP items are only for the times where you are extremely fed and your enemies are complete nooblords. Buy either a Rabaddons Deathcap or a Deathfire Grasp to top off your AP in this build.
Situational items are for the times you are versing a diamond 1 LeBlanc in lane. Either purchase Abyssal Scepter, Athenes Holy Grail, or a Frozen Heart, depending on who is destroying you, wether its the Diamond 1 LeBlanc APC or the Bronze 5 Draven ADC will decide what you buy.

If you are doing well:
Q/W/Q/E/Q/R/Q/W/Q/W/R/W/W/E/E/R/E/E
If you are taking loads of AP damage:
Q/W/Q/E/Q/R/Q/E/Q/E/R/E/E/W/W/R/W/W
Maxing your Q first allows you to burst a Quarter of the enemies health down at once! This is great in teamfights. Your W should CLEAR minion waves at level 4 and the casters at level 3. Keep this in mind. Finally, your E is the best shield in the game for spells, it blocks the damage and disables the effect, if there is one. Pairing your Q, R, then W is a great combo to destroy 1-5 enemies all at once!

Your basic combo for poking should be Q, then W.
If you can execute the killing blow, use Q, E, R, then W to do maximum damage!
*Note* Your R will cancel if you get out of range of the enemy you lock on to.
If you are trying to escape, try Q then E, great for disabling your enemies movement and abilities, while still doing great damage!

Pros:
Great passive, helps sustain in lane.
Loads of damage with Q + R combo!
Your W is an amazing wave clearing ability!

Cons:
Morgana is very slow, hard to escape.
Can be silenced, which makes her somewhat easy to counter.
Can make or break games, *Not always a good thing.

ALWAYS disable the carry on the enemy team. If your team has any sense, they will go for the rooted one first, since its an easier kill.
If the enemies are grouped up in an area, try to "Wombo combo" them with your ult. Jump into the fight, ulti, then Zhonyas. This pairs very well with Jarvan's ult!

Use your W in the very center of the creep wave to get most of the creeps, if not all. Morgana is great for farming when her W is past rank 4.

Morgana is one of the best AP champions that the game has to offer. If executed properly, she could carry the team very well, while having a support component to her skill comp. I hope you enjoyed my guide to Morgana the Mid Maniac. Have a wonderful time destroying with her! :)