I warehouse 99.9% of all my images, let me see if I can explain my process.
1st off warehousing is simply the term thats come about for the storing of your images (and pdf etc) on a server, be it the one your site is on or another one, there’s nothing complex or clever about it.
I use Transmit to access my hosts servers, its just an FTP programme and there are others out there.
Here’s a screenshot of this site viewed in Transmit: https://infinit.io/_/37g45dT
The highlighted files are the site as exported/Published by Rapidweaver.
Now for the warehousing bit:
I create a folder called Assets and then in there I create (if needed) subfolders which contain the images/pdfs/whatever, here’s a screenshot of the Assets folder expanded https://infinit.io/_/SyaFVcU
I then right click on one of the files and select ‘Copy URL’ and I can then paste the link straight into whatever stack I’m using that supports warehousing images (99% of them)
The path will look like this: http://www.nqca.eu/assets/flags/Flag-UK.svg
And that is it.
I use the name Assets because it starts with an ‘A’ and will be at the top of the list, others use a folder starting with ‘Z’ so that it will be at the bottom, other than that we all do it essentially the same.