knitting math

For anyone interested in writing their own knitting patterns or altering the ones already out there, I found this article. And if you know any other resources for knitting math leave a comment. I usually use a pattern as a guideline and then alter it myself, but sometimes the increase/decrease ratios are tricky for me. Any solutions or tips?

I just got a package from my friend Jessica in Tennessee and this was inside....

Gorgeous, fluffy Llama and Alpaca fiber!

And the same fibers handspun! Wow, she is the greatest. She got these goodies at an alpaca farm near her house (Jess- let me know where and I'll post it). Im planning on making an earflap hat sort of like this, but without the waves or peace sign over the ears. Im going to try to work up my own pattern so hopefully it'll turn out right.