It's nice if you can be consistent and accurate with each time you measure, doing it exact. Try, or get a professional who has practice to do this for you, there are thousands of links that outline body fat protocols and diagram exactly where to mark the sites and measure. The machines that do your body fat or the body fat by clothing sizes leave a big range but they will work and reflect changes over time. The machines are much less accurate so don't get frustrated with the volatile readings you may get from test to test.
I have a great scale that is pretty accurate with my weight, and know this by trying a few scales to compare. Having your weight is useful, it can go up even if you lose fat but are gaining muscle so don't freak over the ups and down, use it for your progress charting only, to see changes. At times for me I get leaner and it goes up, and I love it! Muscle is very dense and weighs more than fat so someone who looks bigger may actually have less muscle, body composition means fat, muscle, water, bones…….that's why I like to use a combo of these stats to narrow down a more accurate picture of where the physique really sits.
The day before you test, doing the test first thing being best, don't go on a salty food bender or booze.
You can read your scale before or after you pee, morning or night, but whatever you do just make sure it’s the same time each day and repeat the pattern. I like to weigh in first thing upon waking up and after a pee. Wear the same thing each time or go naked, but again just do it the same every time. Monthly is good enough for most of us, with me I change a lot fast and sometimes weigh weekly or bi monthly. Measurements I do not do more than once per month.
We will look at some other assessments tomorrow that focus on function, strength and flexibility of your body.