Forget trying to use a pattern right now. Just do some meandering, then you can't do something wrong. You can do it close together(stippling) or further apart for meandering. You can do loops and swirls or puzzle pieces. It'd all fun and it holds a quilt together. After you are comfortable with this technique, you can start developing some simple patterns like echoing and go from there. Just relax and it will come.
If you are quilting on a machine, I think SITD is one of the harder things to do, especially if you are using a mid arm or long arm. The speed of the machine is so fast, that you have less control.
Virginia