It surprises and shocks me to see how many print designers fail to use a grid. How big should I make the logo? How long should the lines lengths be? Where should the hero shot go? Well if you used a grid, you’d know all these questions, everything you have just fits into place.
This goes doubly so for web design, and usage of the grid system with web designers is abysmal. Stick to your grid and you never have to worry about placement of elements again, and you can spend more time padding your invoice.