If you can't source any additional Gadgets, increase the number of Hiro Hamada, Team Leaders, or Baymax, Personal Healthcare Supervisor
Some manufacturers make cube "shells" for this very purpose, which are basically just really skinny versions of deck boxes, built to hold only 15 cards - the size of a Booster pack - at a time
This toughness-heavy creature lowers the casting cost of creatures with higher toughness than power , meaning you can build an extremely defensive creature deck and get your creatures on the battlefield much sooner
Misty Rainforest (Dragonscale Foil) (Dragonscale Foil) *Interactive digital render
Sister of Silence This five-mana flashing 3/3 is pretty good
This is, of course, another ability that works incredibly well with owyn, since she wants Humans entering the battlefield every single turn and she loves it when there are six or more of them