Mulligans
General Mulligans
You need to remove any threats from your opponent as soon as possible. Getting a body on the board too is a good idea.
Aggro Mulligans
Dealing big damage to a lot of small minions is a good idea. Aggro Druid and Pirates get a number of small minions out early so if you clear them with cheap damage spells or Hero power it should slow them down.
Control Mulligans
Going up against a Control deck means that you'll have more time to find a Sherazin with Journey Below or just start your Jade Ramp with the Jade Swarmer.
This deck is a take on the Sherazin Miracle Deck, but with a Jade Deathrattle filler.
Because so many cards like Jade Swarmer, Sherazin, Aya Blackpaw and Xaril have Deathrattle, Journey Belowis a vital part of this deck, providing a Discover that can be used in reaction to whatever match up you might be having, or if you’re looking to further your Jades with a Swarmer or another Aya Blackpaw, you can do that too. If you need more spells to proc your Gadgetzan Auctioneer, then Xaril can get you two at least, even a bounce spell that can get your more. You’ll end up with so many 1-Cost spells in your hand that a turn 10 Auctioneer-gasm will be a real treat.
Try to get Sherazin out early. He becomes a damage sponge where your opponent has to choose between killing Sherazin or your Auctioneer; the lesser of two evils. You’ll know you’re winning when you have a board of midrange threats that just keep on coming.
EARLY GAME
Focus on keeping damage spells in the early game to maintain board control; things like Backstab, Fan of Knives, Jade Shuriken, Razorpetal (from the Razorpetal Lasher) and Eviscerate. Try to resolve early board threats with your Hero Power.
MID GAME
By now you should have either started a sizable Jade ramp in the 4/4 or 5/5 region or you have Sherazin and/or Xaril out. Xaril is a support card that simply provides two spells, one of which is gotten from Deathrattle and hence Journey Below. You can combo Bloodmage Thalnos with your Jade Shuriken, Backstab and Eviscerate for some extra damage.
LATE GAME
You should have a board full of Midrange threats like Sherazin, Vilespine Slayer and a chunky Van Cleef to end things off. Use Journey Below and Counterfeit Coin on Gadgetzan Auctioneer to draw out more of your deck.