Let say you have a mixin for shadow like such:
@mixin box-shadow($offset, $blur, $color) { -moz-box-shadow: $offset $offset $blur $color; -webkit-box-shado
@numbers1311407 solution is correct, but you can use the @each directive to create a shorter mixin:
@mixin box-shadow($offset, $blur, $color: #999) { @each $prefix in -moz-, -webkit-, null { #{$prefix}box-shadow: $offset $offset $blur $color; } }