Fixed or Fluid? BOTH! (kinda)
When I started out designing super ugly websites for fun, I didn't have much guidance, and so it took me a while to find grid systems at all. My designs had a sort of grid, but they took extra long because I wasn't working off of a grid system. Obviously, discovering grid systems on which to build mockups was a big help to me, but as I began to look more, I found that it doesn't stop there. The coolest grid systems I've found are on ProfoundGrid which has all kinds of different grids, from basic fixed-widths ones to some really complex fluid layouts that include multiple grid widths. The most interesting one to me, though, is the fluid-responsive grid, which I tried to blog about previously but was thwarted by an ill-timed computer crash. Here's how it works: most of the time, the layout is fluid, meaning that it adjusts as you change the width of your window. However, at specific points, it reformats so that all of your content doesn't end up getting squished. This system is super cool for building sites that will work on computers, tablets, and smartphones without having to make drastic design changes. The Profound grid fluid-responsive grid adapts at two different places, so it has 3 layouts (perfect for desktop, tablet, and smartphone) but in theory, you can build a grid that will adjust at whatever widths you specify. Below are 3 screen shots of the 3 different width adjustments on the Profound Grid, and above is a link to their website where you can check out this and their other neat grids.