shift + option + down to duplicate block of code

shift + up/down to select multiple lines of code

option + up/down to move selected code up/down

cmd + d to show 2 cursors to replace a name with 2 selected variable

Zen Coding: section>ul>li*3{Item $} + tab =

<section>
  <ul>
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
  </ul>
</section>

section#products + tab = <section id="products"></section>

section.products + tab = <section class="products"></section>