The discussion about whether to design websites directly in the browser or in Photoshop is a few years old. My thoughts about it, typing as I try to redesign my portfolio:
In Photoshop I have more freedom in terms of not having to find out how to code the styles first. The visual feedback is more direct.
On the other hand, if I do a design in PS, I have to create it again in CSS, so I have to do the work twice.
If I start in CSS, I can specify the content-structure in HTML first and go from there. It’s not a blank canvas like in PS. I already have a great and readable style. I just have to be careful not to screw it up. Plus: when the design is finished in CSS, most of the work is already done.
In CSS though, I will often not do things that take long to implement because I want to see fast results.
Designing in the Browser may be better for somebody who already has lots of experience designing in a graphics-app. Me as not-so-experienced graphic-designer could be better off designing in Photoshop first.
In Photoshop you can switch styles and fonts much faster than in CSS. You can zoom out much better to see the whole image. This is a thing you have to do when you are painting. It’s so important to see the whole picture at once. If it looks good small, it looks good big.