Question: Does anyone know how I can copy my customizations of XFCE's settings plus its appearance to another machine?

The settings for appearance/design, panels, keyboard shortcuts and geany are not there yet, like at all.

So far I have done:

* copied `~/.config/{autostart,xfce4,Thunar}` (not literally like that)
* logged out and back in, rebooted

Resources:

* <https://forum.xfce.org/viewtopic.php?id=4168>
* <https://askubuntu.com/questions/563382/copy-xfce4-configuration-files-from-one-user-to-another>
* <https://superuser.com/questions/677151/how-can-i-migrate-my-xfce-configuration-and-settings-to-another-system>

Some info, which is true for **both** machines:

```
$ pacman -Qi xfwm4 | grep Version
Version                  : 4.12.4-1

$ uname -r
4.10.5-1-ARCH

```

Answer: 
Xfce usually stores its configuration files in `~/.config/xfce4` (as well as `~/.local/share/xfce4` and `~/.config/Thunar`). Copying these directories to your laptop should do the job. Keyboard shortcuts are stored in `~/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-keyboard-shortcuts.xml`, so they should get copied as well. 

It's possible that after you copy the files they are getting overwritten when you log out of the session, thus preventing the new settings from getting enabled. Perhaps you could try copying the aforementioned directories by logging in through a tty?

Note that there's a global set of configuration files in `/etc/xdg/xfce4`, `/etc/xdg/Thunar/`, `/etc/xdg/menus`, etc. (as well as `/etc/xdg/xdg-xubuntu` if you're using Xubuntu). If you're copying the configuration files between two systems having completely different base installations, you'll have to copy these files as well.
In addition to what StrangeAttractor has said (the files being in `~/.config/xfce4`, as well as `~/.local/share/xfce4` and `~/.config/Thunar`), there's a caveat: some of the files are overwritten by xfce even if you don't select the "Save session" when logging out. Also, some of the files are loaded in Xfconf and they're not refreshed until you restart.

Because of that, please follow the steps:

* Log out of xfce before copying the files
* Copy the files from the terminal (CTRL-ALT-F1)
* Make sure the proper permissions are set on copied files (they should belong to wanted user; if not, do `chown -R user:group .config/xfce4`)
* Then restart the computer (do not relogin immediately, but restart)

This should do the trick. (Tested on xfce 4.12, xubuntu 18.04)