Here are the steps to creating and managing custom tags in OneNote:

1. Go to the View tab
   
2. Choose Tags
   
3. Click on New Tag
   
4. Enter a name for the tag
   
5. Choose the icon and color for the tag
   
6. Once the tag is created, you can assign it to any of your notes
   
7. You can then find and sort them using the tags view in OneNote
   
8. To delete any of the tags, select the tag and click Delete from the tags menu