No one wants to waste time on unnecessary things, especially a developer. If you frequently use a command on your terminal/command line, I would recommend creating a command alias to save some seconds (I guess).
I would make it quick, let's assume you want to navigate to some directory from anywhere and you want to avoid typing cd .... bla bla bla bla. So, let's make the alias for this.
Open the terminal and edit the .bash_profile
sudo nano ~/.bash_profile
Add the following line in the file
alias ms='cd ~/Sites/my_site'