For a while now I've been working on a series of BASH scripts to help automate the process of using ARCHISO to make live CD's, or more importantly a live USB with persistent memory. The USB builds can be either plain or encrypted. I think the scripts are finally to a point where I can put them out there and somebody might actually find them useful. The first link below will take you to the documentation so you can see if it is something you wish to pursue. If you are not one to read a manual then the second link contains the scripts, and also the manual so it is not necessary to download both.
If everything works you should be able to configure and run the scripts to make an ISO, and the scripts will then burn the ISO to the destination of your choice. If your target is a USB it will be partitioned, formatted, encrypted if you request, and a boot loader (syslinux) installed. I've included configuration directories and files for two different builds. One is kind of minimal (I3 WM, Luakit web browser), the other more conventional (LXDE and Opera). These are just things I like and are provided as ready made examples. The intention is you would pick your own packages for your own build, possibly using one of the two provided ones as a starting point.
One word of caution, make absolutely sure the entries in the configuration file (as described in the manual) point to the device you want to burn to. If you mistakenly point to a hard drive partition the scripts will overwrite everything on that partition. You'll not be warned if you really want to do this.
Final note, I am not a documentation writer. I've been living with this program for the last 13 months and what might seem crystal clear to me may well make no sense at all to anybody reading the documentation for the first time. Suggest away if you have an improvement to how I could present something.