Hey,
Don't be down about how your fly looks.
I have some awful looking ones, and they catch fish just fine. I am sure yours will do the same!
I first slip it over the hook, then tie it in on the back leaving a small tail .
Then I tie it down in the front.
Sometimes I slip the tubing over foam, so it makes a floating minnow, like the old lure called the zara-spook.
What's important is that you have fun experimenting when you tie.
chris