First start by masking up the edges of the mirror, this is to ensure no paint gets on the mirror itself and allows you to be a bit messy!
Once you have masked it all up paint one coat of our primer & undercoat (undiluted) this doesn’t have to be neat as the matt emulsion will cover any imperfections.
Leave this to dry in a cool and dry area for approximately 4-6 hours
Take your paint and this time a little more carefully paint a coat on top of your primer, this should now be full coverage and hide any mistakes you made with the primer! If not, a second coat will certainly do the trick!
Carefully remove the masking tape whilst the paint is about half way through its drying time (2-3 hours)
Hang your mirror, step back and admire your handiwork!