My favorite cure for the hiccups is drinking water upside down, but according to a surgeon, there is another way. It's called SSMI (supra-supramaximal inspiration) and was developed by surgeon Luc Morris of the Memorial Sloan Kettering Cancer Center.
From The Atlantic:
"First, exhale completely, then inhale a deep breath. Wait 10 seconds, then—without exhaling—inhale a little more. Wait another five seconds, then top up the breath again. Finally, exhale."