It's super easy. First you make a little curl going in one direction. Check it out below:
Then make another one going the other direction.
Then make a third one in the opposite direction of the one you last did. You should have 3 now.
Then you go back and echo the 3 curls you just did. See below:
Then you do it all over again. I know, I know, you look at what I did and you can see that it's not what I do exactly everytime. Otherwise, it wouldn't be freehand, which is what I love to do. I just try to keep it pretty consistant. Eight years of machine quilting and teaching and I never get tired of this freehand design!