You will come across situations where you are at the brink of losing. Don't hesitate to use your gear to survive the night.
A grenade or Molotov cocktail can take out groups of enemies quickly and turn the tides of the battle. You can also store only a certain amount of each gear so you want to use them or you will lose gear when you find them in resource bags.
Don't forget to upgrade your gear as this increases their effectivity a lot!
Choose your gear wisely before each night so you stay atop of the game and nightly threats.