@ansate I can't remember where I learned magic loop. But, I didn't really like it and never use it anyway.

As for stitch markers, it depends what I want to do.

If I want to mark a place where to increase, for example, I use a tiny loop I made from scrap yarn (thin cotton works well) and just move it every round like I would slip a stitch.

When I need to mark a place where I did something last (eg for increasing every 5 rounds) I use a store bought stitch marker and clip into the stitch.