If you do not use nvm, it may be annoying that each time you install global npm package, it asks for super user right. It is fairly easy to solve this problem by adding small configuration to your .npmrc file:

prefix=~/.npm-packages

Now all your global packages will be placed in .npm-packages folder. You need to create this folder manually.

And then add your local npm bin folder to your PATH. I have such line in my .bashrc:

export PATH="$PATH:$HOME/.npm-packages/bin"

I hope this helps someone.