.SASS

.my-element
  width: 100%
  overflow: hidden
  color: blue

.SCSS

.my-element {
  width: 100%;
  overflow: hidden;
  color: blue;
} 

$VARIABLE

$width-variable: 5em; 
.base {
  width: $width-variable;
}  

$base-height: 10px; 
$default-font: 'Lucida Grande'; 
$default-bg-color: rgba(255, 0, 0, 0.5); 
$enable-glossy-border: true; 
$my-special-gradient: left, #ddebb2 0%, #ffffff 100%;  

LOCAL OR GLOBAL?

$default-font: 'Verdana'

.post {
  $default-font:'Lucida Grande';
  font-family: $default-font;
}  

.post {
  $post-font: 'Lucida Grande';
  font-family: $post-font;
}

.specialPost{
  $post-font: 'Verdana';
  font-family: $post-font;
} 

OPERATIONS

.blogTitle {
  font-size: $default-font-size * 3;
  background: $default-background / 2;
  padding: 10px;
  margin: 10px;
    border: {
      color: #13f083 * 2;
      width: $default-border-width - 3;
      radius: $default-border-radius + 2;
  }
} 

NESTED RULES

#admin {
  color: #fe0988;
  p, div > .box  {
   font-size: 1.5em;
    a {      font-weight: bold;    }  }
}

#admin {
  color: #fe0988;
}
#admin p, #admin div > .box {
  font-size: 1.5em;
}
#admin p a, #admin div > .box a {
  font-weight: bold;
}

...REFERENCING WITH &

h3 {
  font-size: 20px;
  .awesome-one & {
    font-size: 24px;
  }
  &.awesome-two {
    font-size: 30px;
  }
} 

h3 {
  font-size: 20px;
}
.awesome-one h3 {
  font-size: 24px;
}
h3.awesome-two {
  font-size: 30px;
} 

@MIXIN

@mixin my-border {
  border: {
    color: #f08901;
    width: 5px;
  }
}

div.myBox {
  @include my-border;
} 

div.myBox {
  border-color: #f08901;
  border-width: 5px;
} 

...with PARAMS

@mixin individual-border ($color, $width) {
  border: {
    color: $color;
    width: $width;
  }
}

div.individualBox {
  @include individual-border($color: #07f741, $width: 10px);
} 

div.individualBox {
  border-color: #07f741;
  border-width: 10px;
} 

...AND DEFAULTS

@mixin special-border ($color: #010101, $width: 2px) {
   border: {
     color: $color;
     width: $width;
  }
}

div.specialBox {
  @include special-border;
} 

div.specialBox {
  border-color: #010101;
  border-width: 2px;
} 

@EXTEND

.user {
  color: #ffffff;
  background: #880912;
  border-style: solid;
}
.premiumUser {
  @extend .user;
  font-weight: bold;
} 

.user, .premiumUser {
  color: #ffffff;
  background: #880912;
  border-style: solid;
}
.premiumUser {
  font-weight: bold;
}