Focus on your diaphragm and try to sense a bubbling/tickling/light feeling centered in it, that peaks right before a hiccup. Once you can sense it, try to keep your attention entirely focused on the feeling.
If you can keep your mind entirely on that feeling as it rises, after a few seconds it ebbs away and your hiccups should be gone. But it's not easy to do that, and if your focus breaks you'll hiccup. Just keep trying.
. Banned in Sweden. SubGenius, Zhuangist, white-hat troll. Defrocked mathematician. Brain problems.