Start with the main gas valve. Turning it clockwise usually decreases the flame; counter-clockwise makes it bigger. Imagine you’re twisting the ear of a reluctant horse. But go slow. A sudden full blast can singe your eyebrows into a permanent surprised expression.
Pro tip: the lowest setting is not always “off.” It’s often a sad, tiny flame that looks like a dying star. That’s fine if you want ambiance for a breakup. For a party, crank it up. Your guests will think you’re a real pyromaniac of style.