How should we shorten or combine prayers when travelling?

So when you're travelling, the sunnah is to shorten the salah, meaning for dhuhr you'll pray two rakah, for asr you'll pray two rakah, and for isha you'll pray two rakah. Fajr and maghrib you keep as normal. With regards to combining, combining is only something that should be done out of necessity. For example, doctors are performing operations and they're unable to leave the operation, so there's more flexibility in regards to that. But it's not sunnah to combine as such. Combining is only there for a need.