I’ve seen books that ask you to make a master sketch (the sketch that lays out the basic rules as well as your deductions, and which you reproduce while working through questions) at the top of the page, and those that advice making it at the bottom.
I don’t think anyone should lose sleep over this distinction, but I have always put mine at the bottom. I like using the largest space for my master diagram because I’ll have a lot of writing working through my deductions. It doesn’t always fit at the top, especially if the right diagram is vertical.
The top space can then be used for “local” questions (meaning diagrams you need to draw to work through a specific question). Just make sure to label the new diagram with the number of the question it refers to.