Plugin Spotlight - Soundtoys Microshift
Microshift is a stereo widening and doubler plugin based on the classic studio trick of delaying one side of the audio along with subtle pitch-shifting.
Soundtoys have based the plugin on two famous hardware units; The Eventide H3000 and the AMS DMX 15-80s.
I like to use this plugin mainly on vocals, although it can be used on pretty much anything. For lead vocals, I will only use a 20% blend but with backing vocals, I will use something like 50 - 100% so that they are ultra-wide and separated from the lead.
You can get a free trial over at SoundToys
Check out how we use this plugin whist mixing vocals for Arcane Roots