Mulligans
General Mulligans
You want to start your mulligan with very defensive options. In Wild most of the decks you will be encountering are very aggressive, so keep your defensive options as a priority. Always mulligan away Reincarnate and Ancestral Spirit as they are cards you want to combo with your Deathrattle minions.
Control Mulligans
Against control, try to cube early so you get lots of value from your deathrattles. White Eyes is going to give you lots of value in the late game. Getting multiple copies is very strong. Furthermore these copes get brought back by N'Zoth for final finishing moves. Same goes when you up against combo, try and play as aggressively as possible, you can easily fill the board with large threats
This is a really fun Control Shaman deck that works reasonably well with the new expansion. Not only that but its very fun to play and satisfying to pull of.