As I look at most support guides, I am surprised that no one talked about Doran's Shield as much as Ancient Coin start in Mobafire.

Seriously, I start out Doran's Shield 9 out of 10 in Support Start. Unless I am 100% sure that I am winning the lane, I start Doran's Shield. It really helps lane dominance because while Ancient Coin might give more GP10 output for later, in lane, you can tank more damage, regen it quicker, WHILE Blocking 8 Autoattack damage for all-in trades and pokes.

And besides, if you do start Ancient Coin you will be 180 Gold ahead by 5 minutes (That is when you usually go back). That is 1 Pink Ward and 1 Stealth Ward. But if you snowball off of all-in trades and pokes and zone their ADC? That's more than 180 Golds. If your ADC has 10 more cs than the opponent, that's roughly 180 Gold. But think about the experience advantage when it comes to zoning the experience also, and ADC can do better things with 180 Gold advantage. Also, while 180 Gold, I admit, can be the difference between Sightstone, with AD Carry, it may be the difference between Berserker's Greaves and Doran's Blade for a B.F. Sword. That's huge AD difference for all-in fights. However, when it comes to supporting, you just can buy wards to put out Sightstone for now, and it won't affect the lane as much.