One of the trickiest things when working with Rulers and templates is to maintain them stable on the quilt sandwich when quilting.
I have experienced it and I remembered when I first started using quilting rulers for domestic machines sometimes my stitches went out of the track. But I did not know one smart trick- to use a grip tape.
After trying different types of Grips and Tapes, I found one it presented to be the best for me- the Non-slip Grip Tape.
This simple solution has really upgraded my quilting ruler skills!