How to Use Bootstrap SCSS at Visual Studio 2015
Table of Contents
Introduction
How can you use Bootstrap Sass in Visual Studio? There are many ways to achieve this, but you can simply use NuGet with Visual Studio along with the Web Compiler extension.
Install Bootstrap Sass via NuGet
Use NuGet to download the Sass Bootstrap package to your web application.
Twitter.Bootstrap.Sass
PM> Install-Package Twitter.Bootstrap.Sass

Install Web Compiler
Once you have installed the Bootstrap files in your application, you can install the following Visual Studio plugin to compile the Sass to CSS.
Web Compiler
This web compiler will compile the Sass into a CSS file for you.

Conclusion
Using NuGet to install Bootstrap Sass and the Web Compiler extension to compile it is the simplest approach in Visual Studio 2015. If you want to customize Bootstrap further, the easiest way is to use a tool like http://bootstrap-live-customizer.com/ to get the variables.less and bootstrap.css. Avoid using only the customized bootstrap.min.css, as it will be hard to maintain what has been customized.