Just had a few minutes to check out the "I am baker" blog.... I saved it as a favorite!! it's really nice!!
mycakeschool.com has a tutorial on the petal effect and its a little different than I am Baker, using a 12 tip and offset spatula. That's the technique I used and loved the outcome.
It looks to me like mycakeschool.com requires a 1 year membership for $30.00 to see the tutorials.
I feel like I've gotten my money's worth from mycakeschool as there aren't any classes near me to take other than Wilton.
i belong to yummyarts.com and their membership is $19.95 will worth the money, you will love it.