Resizing Xterm fonts with Ctrl+<plus> and Ctrl+<minus>
Xterm misses the convenient option to resize the fonts with Ctrl+<plus> and Ctrl+<minus> like xfce4-terminal or gnome-terminal do out of the box.
This feature can be added on Debian systems by dropping a configuration snippet into /etc/X11/Xresources/x11-xterm-fontsize:
! Allow XTerm font size to be changed with Ctrl+<plus> and <minus>
XTerm.vt100.translations: #override \n\
Ctrl <Key> minus: smaller-vt-font() \n\
Ctrl <Key> plus: larger-vt-font()
XTerm.vt100.translations: #override \n\
Ctrl <Key> minus: smaller-vt-font() \n\
Ctrl <Key> plus: larger-vt-font()
Any new X session will inherit this configuration and Ctrl+<plus> and Ctrl+<minus> will work to adjust the font size (and taking the window size along).
The font sizes that Xterm iterates through can be viewed on the Ctrl-<right click> context menu:
NB: The context menu allows to switch the fonts on systems where the above snippet has not (yet) been installed. So good enough for a one-off.