amok

/home/amok/.local/share/applications/

go there and you will find custom launchers, like the file `noisebob.dekstop´

[Desktop Entry]
Version=1.0
Type=Application
Name=noisebob
Exec=thunar /home/amok/noisebob
Icon=/home/amok/Pictures/NOSIE/noise2.jpg
Categories=Amok;

if you need to have your own category for any reason, you must edit ~/.config/menus/xfce-applications.menu

very easy

further editing in ~/.config/xfce4/panel/whiskermenu-1.rc