I am a middle school teacher and find the following method to work very well. While it won't help you get rid of your own hiccups, it could help you help someone else. When a student stays they have the hiccups, I immediately start asking them questions about a random topic. My favorite is to say, "When is the last time you saw a white horse?" The kids go into all sorts of scenarios and as they answer, I respond with other questions determined by their responses. For example, if they say they've never seen a white horse, I will ask if they are sure they've never seen one in a parade or something like that. I engage them in conversation for about 3 minutes with rapid questions but never indicating what my purpose is. After the conversation, I ask, "So, do you still have the hiccups?" They almost never do. I am not sure why this works. The science teacher on my team thinks it is because they breathe properly as they answer and they have their minds on something else.
Sit on the edge of a chair (keep your back straight) cross your arms over your chest, then take a deep breath (hold it in) and lean forwards so that your head is in between your knees do this 2 or three times for about 30 seconds each and remember that when you come up do it very quickly and take a quick breath then go back down and hold your breath for 30 secs.