$font-stack:    Helvetica, sans-serif;
$primary-color: #333;

body {
  font: 100% $font-stack;
  color: $primary-color;
}

Variables

Great for: colors, fonts, padding, margins, etc.

SCSS

body {
  font: 100% Helvetica, sans-serif;
  color: #333;
}

CSS

$base-font-family: Helvetica, Arial, sans-serif;
$base-font-size:   16px;
$small-font-size:  $base-font-size * 0.875;
$base-line-height: 1.5;

$spacing-unit:     30px;

$text-color:       #222;
$background-color: #fdfdfd;
$brand-color:      #2a7ae2;

$grey-color:       #828282;

nav {
  ul {
    margin: 0;
    padding: 0;
    list-style: none;
  }

  li { display: inline-block; }

  a {
    display: block;
    padding: 6px 12px;
    text-decoration: none;
  }
}

NESTING

Helps minimize selector specificity and can help keep things DRY.

SCSS

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

nav li {
  display: inline-block;
}

nav a {
  display: block;
  padding: 6px 12px;
  text-decoration: none;
}

CSS

Beware the nesting rabbit hole.

.root {
  width: 400px;
  margin: 0 auto;
 
  .links {
    .link {
      display: inline-block;
 
      & ~ .link {
        margin-left: 10px;
      }
 
      a {
        padding: 10px 40px;
        cursor: pointer;
        background: gray;
 
        &:hover {
          background: blue;
          color: white;
          font-size: 700;
        }
 
        .icon {
          margin-right: 5px;
          @include selector-modifier(-2 ':hover', 1 suffix '.zh') {
            color: red;
            background: green;
          }
          @include selector-modifier(-2 ':hover', 1 suffix '.en') {
            color: yellow;
            background: green;
          }
        }
      }
    }
  }
}

.Root.Link.link.a.icon

Wayyyy more qualified than it needs to be.

// Mixin to remove the need to add Vendor Prefixes

@mixin border-radius($radius) {
  -webkit-border-radius: $radius;
     -moz-border-radius: $radius;
      -ms-border-radius: $radius;
          border-radius: $radius;
}

Mixins

Sass Mixins are functions that allow you to complete repetitive or complex tasks quickly. 

Mixin

.box { @include border-radius(10px); }

Implementation

Mixin for Media Queries 

$break-small: 480px;
$break-medium:768px;
$break-large: 980px;
$break-wide:1200px;


@mixin respond-to($screen) {
  @if $screen == handhelds {
    @media only screen and (max-width: $break-small) { @content; }
  }
  @else if $screen == phablets {
    @media only screen and (max-width: $break-medium - 1) { @content; }
  }
   @else if $screen == tablets {
    @media only screen and (min-width: $break-medium ) and (max-width: $break-large - 1) { @content; }
  }
  @else if $screen == defaultbs{
    @media only screen and (min-width: $break-large) and (max-width: $break-wide - 1) { @content; }
  }

  @else if $screen == wide{
    @media only screen and (min-width: $break-wide) { @content; }
  }

}

(Media Query partial currently being used on Pivot)

Use Example

.element {
  float: left;
  width: 250px;
  @include respond-to(handhelds) { width: 94%;margin-left:3%; float:none;}
  @include respond-to(phablets) { width: 80%; margin-left:10%; float:none;}
  @include respond-to(tablets) { width: 150px; }
  @include respond-to(defaultbs) { width:200px; }
 }

.message {
  border: 1px solid #ccc;
  padding: 10px;
  color: #333;
}

.success {
  @extend .message;
  border-color: green;
}

.error {
  @extend .message;
  border-color: red;
}

.warning {
  @extend .message;
  border-color: yellow;
}

Extend/Inheritance

Share a collection of properties from one class to another.Helps keep SASS DRY. 

SCSS

.message, .success, .error, .warning {
  border: 1px solid #cccccc;
  padding: 10px;
  color: #333;
}

.success {
  border-color: green;
}

.error {
  border-color: red;
}

.warning {
  border-color: yellow;
}

CSS

Some Advanced Notes:

Extend Source Order:

Courtesy of Hugo Giraudel

.half-red {
  color: rgba(red, .5);
}
 
.message-error {
  color: red;
  @extend .half-red;
}

This

.half-red, 
.message-error {
  color: rgba(255, 0, 0, 0.5);
}
 
.message-error {
  color: red;
}

Generates This

.message-error {
  color: red;
  color: rgba(255, 0, 0, 0.5);
}

Not This

@extend works by inserting the extending selector [...] anywhere in the stylesheet that the extended selector [...] appears.

Some of his best Best Practice suggestions:

• Make sure the extended selector is present only once in the stylesheet.
• Avoid extending from nested selectors.
• Avoid chaining @extend directives.
• Don’t try extending from within a media query; it doesn’t work.

Check out the post

Responsive Grids:

Custom Grid  

Vs.

Twitter Bootstrap

Twitter Bootstrap 2.32 (Pivot, Mosaic(?) )

5KB

3KB

Well, It can really make a difference in your existing work through refactoring.

Quick Touch on

Advanced SASS 

Control Directives

Takes a condition, returns style if TRUTHY

@mixin text-inset($colour, $opacity: 0.7) {

  @if lightness($colour) < 50% {
    // if the text colour is a dark colour
    // we need a white shadow, bottom, right
    text-shadow: 1px 1px 1px rgba(#fff, $opacity);
  } @else {
    // else it must be light so we need
    // a black shadow, top, left
    text-shadow: -1px -1px 1px rgba(#000, $opacity);
  }

  // set the text colour
  color: $colour;

}

curtesy of 12dev.co.uk

$background-colors-list: #4BC2A5 #606F40 #6648CA #6B6022 #2F54E9;
$border-colors-list: #ff9900 #77ff66 #73C227 #C23E50 #7BAFC2;
$colors-list: #111 #222 #111 #444 #555;
@for $i from 1 through length($colors-list) {
    .stuff-#{$i} {
        color: nth($colors-list, $i);
        background-color: nth($background-colors-list, $i);
        border: 1px solid nth($border-colors-list, $i);
    }
}

Curtesy of Benfrain.com

Iterates over contents set number of times based on variable.

Tools using SASS

http://compass.kkbox.com/

http://mhs.github.io/scout-app/

SCOUT

Koala

GUI Sass Compilers:

Sublime Text 2/3 with Sass builder

Text Editor

Atom.io with LibSass plugin

Visual Studio!