i have icon 2s and a giro encore helmet.
i put the icons backwards so the "L" side is on my right side and same with the "R" around my neck because when they are upside down the seem to fit the ears better this way
i put my helmet.goggles and everything on.
then where there are the 2 straps that connect to make the chin strap. go over the back one with the icons and tuck them under the front one closest to your face.
mine seem to stay in perfect