1. Edit the ‘.profile’ file inside your home directory (e.g. /home/yourname ).  You can use vi or pico to edit the file.  My personal favorite is pico. Easiler to navigate.
e.g. pico /home/yourname/.profile
2. Add your alias commands to the end of the file
e.g.  alias dir=”ls -al | more”
3. Save the file
4. Reload the profile by typing [...]