export CDPATH=.:~/projects
    export PS1="$(uname -n)$ "
    alias ltr='ls -ltr'

More of a procedure, always list file and edit the command before deleting it:

    $ ll file.txt
    -rw-r--r--  1 zera  staff  0 Jan  7 20:28 file.txt
    Ctrl-p, Ctrl-a, Ctrl-d, Ctrl-d, r,m
    $ rm file.txt

So this is a sanity check to avoid this mistake:

    $ rm *.txt

*Edit, one more:

Ensure you overwrite a file (or aren't):

    $ cp -i ~/file.config /etc/