I frequently need to execute random commands in my shell. To achieve it I pause Vim by pressing Ctrl-z, type command and press fg to switch back to Vim. The fg part really hurts me. I just wanted to hit Ctrl-z once again to get back to Vim. I could not find a solution, so I developed one on my own that works wonderfully with ZSH.
Source: http://sheerun.net/2014/03/21/how-to-boost-your-vim-productivity/
Credits: