Add a Fibonacci Grid
If you’re a bit of a number pervert, you probably like the Fibonacci sequence. With GuideGuide, you can incorporate your numerical enthusiasm in your designs. There are a few ways, but this one feels like the easiest:

Navigate to the Custom tab.

Select your document, page, artboard, or an object. This will work anywhere.

Enter this in the Grid Notation field:
 1%  2%  3%  5%  8%  13%  21%  (vnl)

Click the Add guides button.
In this particular version, we’ve created guides that use percentages to express the Fibonacci sequence. The v
in the options block tells GuideGuide to create vertical guides. If you add up each percent, you’ll end up with less than 100%, so you’ll have a bit of a gap on the side that isn’t exactly true to the sequence. If you want, you could do something like this:

Navigate to the Custom tab.

Select your document, page, artboard, or an object. This will work anywhere.

Enter this in the Grid Notation field:
 ~*1  ~*2  ~*3  ~*5  ~*8  ~*13 (vnl)

Click the Add guides button.
Here, the ~
is a wildcard, the *
tells GuideGuide how many times to repeat the command before it, and the 
tells GuideGuide where to put guides. GuideGuide will equally divide the overall space between the wildcards, so you end up with a grid that proportionally distributes guides according to the sequence. This version is a bit more flexible, in that you can continue to add more elements of the sequence without overflowing the available space the way the percentage based version does.