Talked this over with a woman who teaches how to MQ with Janome's. She was very encouraging -- just do it, you'll never get any better without trying!
Her advice to starter:
1. Get some muslin, make some 18" sandwiches, put on various designs -- yours or others. And start.
2. Throw the first one away. (I made mine into a pocket for an ice pack.)
3. Use the second and third, even teh fourth for a pet pads -- donate them if you don't have pets.
4. Do a small project and give it away.
5. By then, you'll feel comfortable trying somethign a bit larger and more technical.
I'm still practicing on give aways, esp. if it's not straight lines or SID. Add these thoughts to the others you see here and have fun!