[Skarg]

I've done all of the above.

My preference after lots of experience is what Shostak wrote: i.e. more often than not, I draw things naturally without regard to any grid, and then overlay a grid for combat.

But when I started out, I appreciated the megahex labyrinth system's ability to let me map out a larger-scale location efficiently for rapid conversion to laying out combat on photocopied megahexes. As a beginner, I wasn't really bothered by the world being made up of megahexes.

As I got more experienced making such maps, I took to actually indicating a lot of irregular detailed terrain, generally by drawing carefully inside the hexes, as if each hex were partitioned into smaller hexes.

I still think it's a valuable mapping scale to use for larger areas, and often my play situations involve more moving around than combat, so in practice for me, only a fraction of the space in a location ends up seeing combat.

However, there is another really fun and engaging play mode where there is almost always a map on the table showing where the PCs are... and for that, yeah, there would need to be tactical space for everyplace, though I think labyrinth scale would still be useful, unless every location explored is fairly small.