I am practicing now on my Janome, too, and making some slow, very slow, progress. Here are some simple things I had to do:
1. Read the manual carefully & follow everything it says. Like, mode & pattern number, correct foot & tension settings.
2. Use gloves to help slide the fabric. It's amazing what a difference that makes.
3. The machine sounds like it's racing, but you should not feel the need to speed along. My problem was that I tried to race through the pattern and couldn't control where I was going at that speed. Now I am taking my time and just practicing control with simple circles and even straight line patterns. Take a deep breath and slow down!
I'm seeing a big improvement in just slowing down. I made a lot of sandwich blocks from an old mattress pad and some old "ugly" fabric. Sadly, everyone is right about practice, practice, but I now think I'll finally get the hang of it. Don't give up.