LOTS of good advice here!
I've found what works best for me was to watch as many of the videos as I could and then just practice, practice, practice. I had a lot of old shirts that I cut up and used those for my quilt sandwich to practice. I mostly do squiggles and I try to relax and I just don't care about being perfect cuz in the end no one is going to examine every stitch.
The main thing is to relax and take your time. I don't like to stitch too close so the quilting usually goes pretty fast.
Enjoy!