I've started to play thresh support, and I want to know what runes I should bring, I do usually run low on mana at the beginning, since I play with people like Graves, Lucian, and Vanus. I play an aggressive start, trying to hook as soon as possible, and keep hooking/flaying from there on out. What type of runes should I bring that will help me, and my adc have a stronger early game, not so worried about late-game.
When playing 
I usually run something like
Armor Quints AD Marks Armor Seals MR Glyphs
Gets all that defense in and then a little extra damage.
I usually go pure tank. armor, scaling armor, MR, scaling MR. then all tank masteries. then just take an income trinket, and start rushing a sight stone for health and wards. its a great support build because most people play carry picks and tanks seem to be lacking now a days to the point where they mostly fit in as junglers instead of top laners. but a support tank its a pretty good combo as you fill 2 rolls with one champion.
I wouldn't get MP regen runes, just get a mana pot at the start, and buy a couple each time you back.
You mostly want to run defensive runes, but I like to take 2 GP10 quints as well, personal preference.
