Correct process to update the npm packages?

I am still a little confused as to update and what is the correct order. I have a package ncu to update both global and local packages.

In addition to updating the package.json

But I'm not sure I do it right I would like to update the global, local and update packge.json first

The line of commands I use are:

• ncu -n -u
• ncu -a
• npm update
• npm update -g
• npm install

How do you do it?