How can I always show my user's 'library' folder in macOS Sierra?
Yes. Probably the easiest way is:


Click on the Finder icon in your Dock (usually the very first icon)
In the Finder window that appears, click on your username in the Sidebar (see note at end if it's not listed)
Now go to View > Show View Options (or press commandJ)
Now tick the Checkbox next to the Show Library Folder option (it's the bottom checkbox - see screenshot below)





Now your Library folder will remain visible as you were previously used to.


NOTE: If your username is not visible in the Sidebar, then go to Finder > Preferences, select the Sidebar tab and then select the checkbox next to your username at the bottom of the Favourites list.