Welcome to Kopsu Himself's Morgana everyplace, everyday, everyteam guide to success.
I have played Morgana for years so I think I know something :P

Morgana is quite simple to play and on the following I will tell you more about this champion.

I would choose MP&AP runes for maxium damage at the beginning to get few kills. When you get few kills and nice farm with pool you get the item rotation up and rolling. :) You dont need hp runes or something because E shield is so powerful.

If you like it more safe, you can choose couple hp runes.

Masteries... well those are the once that I use. You can add your own spices if you want to :)

That is the best item rotation. Rod of Ages for the start. Nice hp and AP. After that shoes and hourglass. I personally think hourglass is very important, you just go to teamfight pop ulti and then click hourglass for the "You have slain an enemy" sound. :)Just keep on eye for for magic res or something else if you need them.

Flash & Ignite is very nice combo. You can use teleport if u want to, but I preffer flash.

Passive = You dont need to buy spell vamp, this replaces it. Very usefull. Very good against long range champs with low mana spells and dots likeand

Q = Dont use when there is a lot of minions. First wait your ulti stun, then throw Q.
W = Your bread and butter, when it comes to farming. When you are lvl 5 you can kill waves except big minions.
E = Good in teamfights and also mid laning aswell. You can the deal, when you are in action pop it, just in case.
R = One of the best ultimates in game. Very powerful. In teamfights flash in the middle, pop ulti and then hourglass. Hell of a combo.

I suggest you to call for mid always. You can also play bot lane, but she aint that good at bot. When your pool gets to lvl 3 the farming becomes to a piece of cake. All the minions die (except big ones) if you place the pool right.

You can play aggressive and push quite easy in mid. Just try to snare&pool enemies to do damage to them. If you got AP against you just shield in combat. If you are against an AD champ, stay back and harass. When you get ultimate you can play more bravely.

Getting the full potential out of Morgana requies practice, practice and practice, just every other champ. When you start to hit with Q you are strong. I hope I helped just that little to make the difference between carrying and feeding

-Thanks for reading