When that happens, love will steer the stars.
It may be of interest that Jupiter passed Saturn from the Sun’s perspective in October, that was a “heliocentric” conjunction and our looming event is a “geocentric” conjunction, as we are somewhat off to one side of that line (were at right angles to it in October which is why the planets did not appear as close then to us).
This will be a difficult sight to locate for viewers in many more northerly locations where skies are often cloudy in December and the apparition will be rather close to the southwest horizon after sunset. It will be relatively easy to spot on a daily basis in the southern U.S. and other lower latitude spots.
You need a good unobstructed view of the sunset (which will be towards the southwest or at least west-south-west for most, as the two planets won’t be as high up in the sky as you may remember them being in September or early October. That will become more relevant each day into December. A nice sight before the actual conjunction will appear around 16th and 17th of December when the crescent moon passes the planets. By the time of their closest pass (Dec 21) the moon will be at first quarter, meaning you will see a half moon due south at sunset.
Something else to note if you’re into sky sights, the Moon is currently approaching the higher part of its 18.6 year declination cycle, as the 5 degree latitude maximum in its orbit begins to phase with the high point in the ecliptic plane. This means the winter full moons will be quite high up compared to a few years ago, the peak in this cycle is 2024. Despite the fact that Jupiter and Saturn are both a little below our orbital plane at this conjunction, the Moon is lower still so it appears to run below the two planets. Later in 2021 there will be a series of occultations as the planets move lower and the Moon reaches minimum declination relatively sooner each orbit.
It would be quite something if there was a double occultation but I think you would have to be some distance above the South Pole to see that. Observers in the southern hemisphere (where it’s approaching the summer solstice) will have a much nicer view of this pending event. It will be considerably higher in their sky and of course a lot warmer outside.