The simplest way to cut up your homemade fudge is to use a thin, long knife to score it in straight(ish!) lines. However, if you want perfect squares, you will need to use a measuring tape and score lines at carefully measured intervals before slicing all the way through. If you plan to make more fudge recipes, I recommend you make a template on some cardboard to save you having to manually measure each time! Oh, and if the fudge seems to crumble when you cut it, warm the knife blade a bit then try again.