Lazy Featherer...
At first I was afraid of feathers - and it turns out that I was running into the center spine, instead of making teardrop shapes and following far enough down the center line. I've finally decided I'm a lazy quilter - I leave the center spine out! I use cheap white school chalk (no wax) to chalk a curvy spine, then quilt teardrop shapes on both sides of the line, and dust off the chalk when I'm done. Also, I am not concerned if the feathers meet at the sides, I leave a space in between. I like the look of it, I can relax and breathe, and this seems to work great for me!
Sometimes you are more comfortable making feathers from the bottom up, (or from the top down), so one side of your motif looks great and the other, not so. Practicing will help, or just tie off at the top and start again at the bottom if it's more comfortable.
I also go to my local newspaper and ask for newsprint bolt ends, which makes great doodle paper. I roll it out across the kitchen table, grab a pencil or marker and practice my motifs. Really helps with muscle memory. The smoother your lines are in practice, the smoother they'll look on the quilt.
Feathers don't have to be curved on the end. Come to a point and you've got sunbursts, ferns or peacock feathers.