I never follow patterns either. I see something and adapt it my way. I agree that a log cabin is a great way to start. Have you seen the techniques done by Ricky Tims? I love his techniques. He teaches you to "follow" a pattern while doing your own thing and the results are amazing. I love convergence quilts the most. I took his super seminar last year and never quilted the same way again.
You can see some of his pieces at www.thequiltshow.com
Maria