Hey just recently started playing Soraka. This is how I play her (usually ends in victories)
I go full into the Tanking mastery tree with a bit into Utility, my rune page is almost all cooldown reduction, in game I start with mana manipulator, never get starfall (until I absolutely have to if it's later in the game and i'm high level), if there isn't a veigar i get that item that increases your mana each time you cast a spell, then go for survivability items (magic resist boots, that item/shield which gives allies an armor magic resist and damage aura, then work towards a guardian angel
I'm no Soraka pro or veteran but that seems to work, or am I playing her wrong? I really never get anything to increase her ability power, should I forgo some of the survivability items and go for more ability power? should I not be in the tanking mastery tree?
also would it be worth spending some points to get that damage mastery skill which increases your ability power by 0.60 or whatever it is per level
thx, gl hf