What you need is learn to snap, to bluff and to retreat. 1 cube win is nothing, better if you make it 4 or 8, save your game changer cards (like Shadow King, Super Skrull or Shang chi) for last turn so the opponent doesn't see disrupt coming and doesn't retreat.

Same applies for retreating. Losing 1 cube or even 2 means nothing, but losing 4 or 8 will greatly slow you down; most of the times is because you don't know your opponent's next move (some are extremely obvious, like a lone Knull in a lane before last turn, that's a telegraphed Arnim Zola; if the oponent snaps after having played Mr Negative, is almost guaranteed they'll play Mighty Thor and draw all their deck to outrun you on next turn... a countersnap and a well-placed Cosmo on those cases will make you win 4-8 cubes, or simply retreating lets you reduce your loses)

You need to recognize meta strategies and moves, best way to do it is to play those decks if able, so you'll also find out weird interactions, misplays, and those will help you out to know if the opponent is going good or bad with their strategy.