How to NOT snore
Good options
Mandibular advancement devices
Some types of surgery
CPAP machines
Stay off the booze
OK options
Anti inflammatory medications
Change your sleeping position
Lose weight
Specific physical exercises
Tongue pullers
Silly options
Other types of surgery
Accupressure rings
Things that hurt you if you snore
Magnets
Surgical
There are some surgeries that can stiffen the walls of the airway. This can be done by attacking you with lasers or other burny things to cause scarring of the airway walls. This makes them less floppy and can stop them collapsing. It's also possible removal of fat from the area (by surgery) can make the airway larger and thus less likely to collapse. Exercise can strengthen the muscles that support the airway which can also help. Becoming younger can also help... as people age muscle tone naturally decreases, meaning that the airway becomes more likely to collapse. So on your next birthday cake, try removing a candle instead of adding one. That should help a lot.
Non surgical
There is also a nifty feature in humans that can be exploited to stop snoring. We have the ability to protrude our mandibles - in other words, we can move our jaws so that our chins poke out. Most people can move their chin at least 1cm forward. This is handy, because moving the mandible forward moves the base of the tongue forward too, which increases the size of the airway. This makes the collapse we talked about above much less likely, and in fact it can completely stop snoring in most humans! Yay! Now you just need to make sure the snorer remembers to keep their chin forward while they sleep.