Question: How should I start to think about district planning and city placement the right way?

I have several hundred hours of Civ V and Vox Populi under my belt and I would finally like to break into Civ VI. However, I find that my Civ V instincts get the better of my whenever I am looking to expand and find new cities, e.g. a city with couple of flat tundra tiles might be complete poop in Civ V, but okay in VI, since you can place districts onto those tiles.

Additionally I don't really have a plan of how to spread the districts, just campuses, industrial zones, commercial hubs/harbours, even if in fact I would probably benefit more from a holy cite/cultural district/entertainment complex/dam/canal etc.

So is there a method to the madness or do you just have to experiment enough to sorta learn when you are doing okay, when to divert to other districts and what to build/plan?