Some of us designers over in Ravelry, have been talking about charting crochet patterns. I think many of us who enjoy crochet, really appreciate charted designs. Not only can you see what is going on, but they are fairly well understood regardless of language. Crochet charts pose some unique challenges that knitting charts generally do not. While knitting is suspended from a cord or needle, making each row straight, while you are working it, crochet stitches grow organically from a single point and then tether to the previous row at any point the designer indicates. That means that you cannot simple set up a grid and build your chart. Each stitch may be a different height and width, or clustered together at the base or top, and all of that needs to be carefully crafted in the chart to make it clear what the crocheter needs to do next.
Definitely check out that thread for other tutorials, tips, and discussions, if this topic interests you.
There's certainly no single correct way to make charts, but it can be helpful to see how other people do theirs. Below is a rough take on how I do my own charts. This is a motif-style chart, but many of the steps would be applicable to flat rows, as well.
I lowered my monitor resolution to make everything on my screen bigger, but you'll still probably want to watch this in full screen. If you can't see the embedded video here, here's the link to youtube. And if you want to play around with the finished Illustrator file, I demoed in this video, you can download it here.
