I've been doodling with a piece over at DJCA about calculation and as part of that task I watched a few YouTube videos about how to calculate. Almost none of these actually tell you how to calculate, although several do show you.
Here's one for you to think about from Black's point of view:
Readers disappointed by lack of new coaching material on this site may be aware of the activity on the website of the Devon Junior Chess Association . Most of it is pretty basic and/or already covered here, but I've recently been thinking about calculation, and there is a page How to get better at calculation which I might equally have placed here.
Some time after writing the piece about checkmate patterns, I bought V. Vukovic's
famous book The Art of Attack in Chess. In it he
gives a chapter full of mates, shown below; the numbering and
terminology are his.