i have had semi-chronic hiccups since i was about 15. i think it's mostly psychosomatic because they started when i would walk in the front door each night. i'd walk in and boom, hiccups. i haven't pinned down the exact trigger after all this time so i have remedies.
the one i use most often is controlled breathing. take deep breaths but draw the inhale out as long as you can, get a feel for your diaphragm. whenever you feel a hiccup come on, attempt to burp. sometimes i have to swallow the air during the slow inhale. then i exhale as slowly as possible. once you get in tune with your gut muscles it's just instinctual. it took a while to get the feel of but i can now control the spasms if i'm calm enough.
if for some reason i'm not able to be calm enough to do the slow inhale, i'll basically do the same thing, just with an emphasis on holding the breath. i'll take a deep breath normally, but hold it as long as i can and try to "induce" a spasm. if i feel one coming i do the burp thing.
i can usually get rid of them in 5 minutes this way. all that nonsense about sugar and drinking from the far side of a cup and getting scared is all really an attempt to do what i've described above. it's an attempt to get you to swallow air or reset the spasm. the only real way to do it is to get control of your diaphragm.