It is natural to think to add a post or pre step within the workflow stanza along with orb commands. The correct way to define these along with parameters would be the following example.
Here is an example
#add orb stanza as usual, argocd-orb/default and argocd/deploy commands as example
pre-steps: # steps to run before steps defined in the job bar
command: echo "test pre"
post-steps: # steps to run after steps defined in the job bar
command: echo "test post"