Steps to design custom rules: –

1. Open your Outlook window first.
2. Go to the File tab
3. Select Manage Rules & Alerts present on right side of Outlook
4. In Rules and Alert box, choose new Rules, under E-mail rule
5. The next Rule wizard appears before you in Step 1:  the third option “Start from a blank rule.” Choose one of the two options Apply Rule on the message I Receive or Apply Rule on the message I Send.
6. Moreover, then click on Next Button present at the bottom of the page. Moreover, perform the following.
   • Under Step 1: – Choose Condition(s), various conditions are available tick whichever conditions you want to trigger rule for the message.
   • Under Step 2: – Edit the Rule Description, click on an underlined value of any conditions which you added, and now specify the value.
7. Click on Next Button, and perform the following task: –
   • Under Step1: – Select action(s), the list of activities appears before you choose the work which you want your rule to take when specified conditions are met.
   • Under Step2: – Edit the Rule Description. As before click on the underlined value for any action that you chose, and the determine the value which you want.
8. Click on Next Button and perform the following Steps: –
   • Under Step1: – selection exception(s), various exceptions are present there select any of the exceptions if it is necessary (this is an optional Step) and then click on Next Button
   • Under Step 2: – Edit Rule Description, click on underlined value for any of the exception. After that, you can specify the value for the added exception.
9. Click Next Button and then
   • Under Step1: – Specify a name for the rule, the type whichever names you want to give to your rule.
   • Under Step2: – Setup Rule option, out of three options tick on click boxes for the options that you want your rule to have.
   • Under Step3: – Review rule description, click on the underlined value and choose the option that you want.
10. End the process by hitting on Finish

This is how you can create a custom rule in Outlook 2016 or 2013. Even you can also create a rule from any message or Create a new rule in Outlook for Basic Steps.