For beginners who aren’t yet proficient, are you still using chopsticks as spacers? Not only is the thickness hard to control and prone to slipping, but it can also easily cut your fingers. Try this slicing aid instead. I’ve uploaded an SLDPRT file that lets you customize the thickness to your preference—here, I’ve set it to 3 mm. In your slicing software, select the “magnet negative part” option under objects, then adjust it to match the specifications of the magnets you have on hand; in my case, I’m using standard magnets with an 8 mm diameter and 2 mm thickness.