Customizing Bootstrap Sass

This is my first time to make a tip but i'm not sure if this one will be a good or bad but i just wanna share this from what i learn.

For those Web Designer's or Developer's Using bootstrap sass. You don't need to locate the class name and make another class to overrides the old like this one of my examples.

Your Doing something like this for example the navbar background

//Your Code    
.navbar {
background: #333333;
}

Instead make this one since we are using bootstrap-sass

$navbar-default-bg: #333333;

You can check some of available variable here
link
a special notes remember replace the @ into $ since less is using @