Long time ago I found a binding:
imap <C-v> <esc>"+pi
... and added it to my vimrc.
Don't do it. It's useless and wrong.
You can achieve the same with native
binding, which allows you to paste from any register when you are in insert mode.
So, while being in insert mode, instead:
you can use:
to paste from global register. Or
to paste from system drop register. Or
from system select register (only unix/linux) or use any named register as you like.
You can find more tips like this in the awesome Practical Vim book by Drew Neil http://pragprog.com/book/dnvim/practical-vim