For an easy way to cut out fusing for waistbands, belt loops, straps and other long straight items:
Just buy a roll of fusing and slice through at the width you need.
It makes it so much easier to iron/press onto your fabric too.
Just be sure to cut carefully so it's not on a funny angle, or you'll end up with wavy edges.
I just used a sharp knife on my breadboard. It's much cheaper than buying the small precut rolls of thin fusing too. This 1m wide x 10m long roll of standard fusing was $8 from my local store, compared to $12 for just 3m of fusing precut to a waistband width.
Such a timesaver!