Measure the hoop than I would add three inches to each measurement, If the hoop measures 6x8 as it is usually bigger than 5x7 for foot clearance I would cut my blocks 9x11. I would write down what sizes you like for stabilizer and muslin. I just bought a bunch of muslin the 108 inch backing washed it the hottest water, pressed and precut a ton of muslin for my projects, now I can just grab and go. I have all my measurement written on a post it in my manual for reference, then when done embroidering you can cut them square or rectangle the size you want