It's easy to create a Mac recovery partition in every version of macOS, from Mavericks (and earlier) to High Sierra ...

If you are running High Sierra on a Mac with a Flash drive, or Mojave on any Mac then you don’t need to create a partition at all, you only need to create a new volume.

I want to partition the card so I can use it for an OS install disk (Mac OS Extended GUID) in one partition and as a camera disk (MS-DOS FAT) in the other partition.

This guide is for those people, the ones who want to test the new OS X beta without wrecking their Mac—you never want to put your data at risk by installing beta software on your main partition.