0) Start with the content. Always design around the content and the target audience in mind
1) Starting on pen and paper, I sketch 5-10 layouts in a short amount if time then I try to evaluate them based on gut feelings. This is also a good time to experiment with alternatives, new ideas. Google "webdesign patterns" if you need solutions for a given problem
2) Sketch a black and white HTML+CSS version then try to add the appropriate paddings and margins.
3) I look for inspirations in web design galleries, pinterest, dribble, whatever I can find.
4) Pick a good font for display + text, good typography is key
5) Try to make something that approaches the websites you like, grab a color palette from http://coolors.co, images from https://unsplash.com
6) Iterate
This list is incredibly leaky, but more or less this is the process if I have to design something from scratch.