Creating a responsive website design from the ground up can be exhausting and costly. Thankfully, for those of us without the time or money to completely build a brand new site, there are lots of frameworks or boilerplates you can use.
Chris Spooner from Line25 compiled a bunch of these free frameworks, from the most popular, Bootstrap which was made by the guys at Twitter, to some more obscure but helpful frameworks. They also all have the complicated grids and layouts prepared so you can almost completely customize them.
Responsive design has never been so easy.