I am currently using antergos in the default partitioning with luks enabled but think it is suboptimal and want to change it.

Currently, my root directory is in a luks container, but my swap space isn’t (and is also larger than necessary).

What do I have to do to get a smaller and encrypted swap partition instead?
Can I delete the existing swp partition, extend the luks container, and (sub)partition it to have swap in there. How exactly would that work?