Mulligans
General Mulligans
In general, mulligan for Cloaked Huntress and as many trap/secret cards as you can. The secrets you keep really depend on the matchup. If you have Kindly Grandmother, keep her.
Hunter
They say Hunter is dead, but I’ve seen decent success with this variation of Secret Hunter in ranked play this month.
What originally began as a quest to simply level up my Hunter hero (working towards all golden heroes and cards), my handy Hearthstone deck tracker has shown me that this deck is 24-9 for a 73% win rate in ranked play (February 2017).
Further, I’ve actually had a number of wins against both Reno Warlock and Reno Mage (with Flare being a significant factor vs. the latter).
Bad match-ups are typically Shaman and Reno or Dragon Priest.
P.S. Freezing Trap has been left out because there are so many cards with a Battlecry or action in the current meta that would actually benefit from returning to their owner’s hand.