What's Your Go to Interfacing Method?

Thawell: Interfacing is used behind bound button holes, right up against the fashion fabric. Fusible any time where you have an angled seam you have to cut into. But i think it's not used so much in coutur sewing,. It does seem to me there's always kind of a problem with getting it to stick permanently, consistently. To my mind, it changes the nature of the fabric. So totally.