You can also use gravity. If you have a big enough ball of hydrogen, the gravitational force will make the pressure at the center great enough to cause fusion.

We can see a demonstration of this process by looking up during the daytime.

More seriously, this isn't even true at the power generation level that electromagnetism is the only possibility. Another technique that has showed some promise is popping tiny individual bubbles containing heavy hydrogen with a monster laser.

The downside is the laser - the upside is you don't need magnets or much containment at all and a container breech cannot happen because each individual reaction is separate.