The one most important thing I have learned is keeping it simple. I have never really found any gadgets that really make quilting easier. New gadgets just create a different scenario of issues to work through.
I am not a purist in any sence of the term. I do use "modern" tools but it can all be done with needle and shears. Isn't that marvelous!
I have no favorite gadget or tool. I would have to add that the best thing I do own is a color wheel, which I rarely use but is there when I want it.
peace
:D