Responsive icon solution when changing icon sizes in OS X Finder
You can have the folder contents auto-arranged in icon view via a few settings in View &gt; Show View Options (⌘ Cmd-J).

When you select the files to be Arranged By the criteria you prefer and select Use as Defaults, the icons are automatically re-organised on-the-fly. Note that you don't need to select Always open in icon view, as in the example image below.

These default settings will be used for all folder that don't have folder-specific settings applied, before or after setting the defaults.

You have to restart Finder, e.g. by killall Finder before the new defaults are used.


(Image borrowed from a SuperUser answer)