the only things I have added to my .bashrc are two PATH additions and one env var:
I have a few commands/utilities built from myself, located on a separate filesystem, so are available when dual-booting avoiding duplicates of the commands (mostly shell scripts):
if ! echo $PATH | grep -q "/u/lbin"
PATH=$PATH:/u/lbin ; export PATH
Another addition is a "relative path" (path that doesn't begin with '/' ), I usually build my own software and the resulting executables will be located into the "pc10" directory.
if ! echo $PATH | grep -q "pc10"
PATH=$PATH:pc10 ; export PATH
I can build my project1 in /u/project1/pc10/excutable1 while working in /u/project1, the command "executable1" will be found in PATH
and my project2 in /u/projetc2/pc10/executable2 while working in /u/project2, same as above the "executable2" will be found in PATH
This allow for an "easy" launch of the applications while they are "work in progress", without any type of installation.
The surrounding "if" are needed to avoid multiple inclusion of the same directory in PATH.
Finally I have an env vars, it was needed to edit comments before to commit some additions to a project located on a SVN server.
SVN_EDITOR=vim ; export SVN_EDITOR
nothing too much fancy!