Hearthpwn

I never really got past rank 10 but this deck seems promising and got me to 7 in a few games. Will keep you updated if I reach any higher!

The main idea of this deck (as with any other ramp deck) is to survive the early game, ramp up and play big threats to close out the game.

Here are some mentions for specific cards:

Forbidden Ancient

Now this card is awesome.  I know, valuewise this card is total crap, but it can really help you keeping up the tempo and filling out your mana curve.

In ramp druid especially you often have a hand full of expensive cards and no ramp to get to them so you have to pass the turn. Another example is when you have to remove something from the board (e.g. with Wrath), but then you don't have enough mana to play your big dude.

Only play this card in the early game if your really, really have to. Otherwise keep it and try to slip it in in the late game.

Twilight Elder

This card is really important for your early game, so you keep him in your opening hand almost all the time. He get's really strong when you can pull him out on turn 1 with Innervate.

Mire Keeper

Since this deck only has Nourish as a 5-drop, you can play this card out on turn 4 and skip turn 5 to get directly to your Dark Arakkoa or Emperor Thaurissan.

Spellbreaker

This card is not great but certainly better than the nerfed Keeper of the Grove. One is enough though.

Nourish

Since Ancient of Lore got nerfed, this is your main card draw. Never use it for ramping! Sometimes it's difficult to play it because you lose so much tempo, so try to plan ahead and control the board first.

Twin Emperor Vek'lor

This card is ridiculous. New Dr. Seven.

Soggoth the Slitherer

This card is awesome against Mages. But also other classes really struggle with this card. He's really great if you need to get back control over the board and it also just feels nice to spend the 9 mana (or less) and to know that your opponent cannot play a cheap removal to kill it.