SCSS Breakpoint Mixin

_breakpoints.scss

@mixin respond-to($breakpoint) {
    // If the key exists in the map
    @if map-has-key($breakpoints, $breakpoint) {
      // Prints a media query based on the value
      @media #{inspect(map-get($breakpoints, $breakpoint))} {
        @content;
      }
    }

    // If the key doesn't exist in the map
    @else {
      @warn "Unfortunately, no value could be retrieved from `#{$breakpoint}`. "
          + "Available breakpoints are: #{map-keys($breakpoints)}.";
    }
}

/** BREAK POINTS FOR MEDIA QUERIES mobile first **/
$breakpoints: (
    'tiny':   only screen and ( max-width: 375px ),
    'small':   only screen and ( min-width: 415px ),
    'medium':  only screen and ( min-width: 768px ),
    'large':   only screen and ( min-width: 1024px ),
    'xlarge':   only screen and ( min-width: 1281px ),
) !default;

To use this, import it into your SCSS file and then whenever you want to add a breakpoint do as follows:

/** import the mixin **/
@import "breakpoints";
/** Mobile version of element **/
.element{
  width:100%;
  /** Add a breakpoint to width for large (min-width:1024px) displays **/
  respond-to('large'){
    width: 50%;
  }
}