1. Example.scss

@include keyframe(fadeout) {
    0% {
        opacity: 1;
    }

    100% {
        opacity: 0;
    }
}

@include keyframe(changecolour) {
    0% {
        color: #000;
    }

    100% {
        color: #FFF;
    }
}

2. Keyframe.scss

@mixin keyframe ($animation_name) {
    @-webkit-keyframes $animation_name {
        @content;
    }

    @-moz-keyframes $animation_name {
        @content;
    }

    @-o-keyframes $animation_name {
        @content;
    }

    @keyframes $animation_name {
        @content;
    }
}

3. animation.scss

/*
    Example usage: 
    @include animation(changecolour, 10s)
    @include animation(changecolour, 10s, linear, 5s)
 */
@mixin animation ($animation, $duration: 2s, $timing-function: ease, $delay: 0s, $iteration-count: 1, $direction: normal, $fill-mode: forwards) {
    -webkit-animation: $animation $duration $timing-function $delay $iteration-count $direction $fill-mode;
    -moz-animation: $animation $duration $timing-function $delay $iteration-count $direction $fill-mode;
    -o-animation: $animation $duration $timing-function $delay $iteration-count $direction $fill-mode;
    animation: $animation $duration $timing-function $delay $iteration-count $direction $fill-mode;
}