It depends upon the stage of your fire. If you’re just getting started, aim the nozzle at any kindling that’s glowing and gently blow air at the embers. This will infuse the area with oxygen and help kindle the flames without snuffing anything out. But if your fire is dying out, you’ll want to aim the bellows at the base of any glowing logs and compress more aggressively. At this phase of the game, you already have heat and fuel — oxygen is most likely the ingredient that’s lacking.