Tip 3: Understand the cost of your objects
Take, for example, these two properties:
-object.innerText //IE only -object.innerHTML
Did you know that the second property demands multiple times the system resources to call than the first? If all you're changing is the textual content of a <div> or <span> and in IE only, innerText would definitely be the more efficient choice. Another example are the CSS properties "display" and "visibility"; the former is significantly more expensive than the later.