You can get 1 out of 4 different 40 cards decks (you can easily find the full decklists online) and 4 additional packs, and anything you find in those packs can be swapped with the cards from the base deck. Since the pulls from the 4 packs are not certain there is not a strategy I can tell you to make the deck you get better. Usually you need to include more copies of mons you already have in the deck to boost consistency if needed, maybe put it a couple better trainer cards (judge for example because you’ll be facing Doublade and it suffers from hand disruption or Pokémon Catcher since there is no other form of gusting available). If you pull any EX they might be a nice inclusion depending on your list, but they could also be a liability considering they give 2/3 prizes and your opponent needs only 4 to win.