Multiple OS on SD card

[bcnaz]

I *thought* I submitted this question already this morning but it seems to have vanished! I'm excitedly waiting on my Pinephone to arrive (US here) like most folks. I figured I'd set up an SD card today and have a 64Gb card set aside for this. 

Unlike most folks here, I'm a very casual linux user, I loooove playing with different OSes and seeing different UI styles - for this very reason, I want to be able to put all the available OSes on a single SD card and if possible, choose to boot between them but I can't find a guide outlining how someone would do this. As a relatively inexperienced linux dude (know enough to be dangerous), I'm not quite sure how to go about the configuration of the SD card. I *assume* I am creating a number of partitions, one for each OS with a partition for the boot manager (u-boot seems to be the first boot manager enabling this) - but I'm not sure how to go about this from my windows laptop as this is the only machine that I have an SD reader available to me.

Does anyone have a guide or set of guides they could point me at to get somewhere?

thanks!

I believe I did see something about the multiple OS booting from a single SD card here elsewhere on this forum,
   but that I think was referring to a YouTube video ???

As far as what computer to use to build your SD card, 
    the USB to SD card adapters are fairly cheap,   a few SD cards do come with an adapter included.

The Pine phone is pretty new, so a lot of these ideas have not actually become finished products as of yet.

I myself have a pile of SD cards I bought in anticipation of my new Brave Heart phone.