\pset linestyle unicode
In my psqlrc I also have a bunch of "macros" (unfortunately no parameters in psql) for common stuff like transaction handling and SET ROLE / RESET ROLE, lock monitoring etc.: https://github.com/hollobon/psqlrc/blob/master/psqlrc.conf
Some of it only works on <=9.4.
\pset null ␀
All these years I didn't know about this.
\set PROMPT1 '%[%033[1m%][%/]%033[0m%]% # '