Common Sass mixins I use.

mixins.scss

// Mixins
@mixin hover-ease($element, $time) {
	-moz-transition: $element $time + s ease;
	-o-transition: $element $time + s ease;
	-webkit-transition: $element $time + s ease;
	-ms-transition: $element $time + s ease;
}
@mixin corners($radius) {
	-webkit-border-radius: $radius;
	-moz-border-radius: $radius;
	border-radius: $radius;
}
@mixin glow($position, $color, $opacity) {
	box-shadow: $position rgba($color, $opacity);
}
// Not really a mixin, but close enough. To use: @extend .clearfix
.clearfix {
  zoom:1;
  &:before, &:after {
    content: "\0020";
    display: block;
    height: 0;
    overflow: hidden;
  }
  &:after {
    clear: both;
  }
}