This process may vary depending on the building, and it may even be different within the same building, since this country doesn't have a clear standard. Here's the general set of instructions to turn on the lights for either direction:
To turn them back off:
Some light switches may be different to this, such as ones that allow you to adjust brightness. In this case, to get it right the first time, you should consult the manual that came with your light switch, or whoever installed it if you did not do this yourself.
If one of these processes don't work, try these troubleshooting steps: