The measurements I'm describing in this post are the ones I'll ask you to take when you're ordering a corset. You'll need a cloth measuring tape and another tape -not necessarily a measuring tape, a long ribbon, a string or something similar is okay- to take your body measurements. You can find these in fabric or haberdashery stores. I'd recommend to ask someone to help you, it's easier and measurements will be more accurate.
If you're willing to order a corset, please make sure you take all the measurements I describe below even if you feel some of them are unnecessary -for example, if you're ordering a waist cincher it will be helpful to me to know your bust measurements.
First of all, you want to be wearing your best bra. Note that a push-up or padded bras are not good to take measurements. Your bra must fit you well, and put your breasts in a natural nice place. The best way of measuring your body will be over your own skin, only wearing your bra.
Now you're ready to start measuring. Take your ribbon or tape and tie it around your waist -measurement C in the drawing below. Usually your waist is the thinest part of your body. Sometimes this is kinda hard to find, specially for big sized people. If that's your case, you can easily find your waist by standing and bending over to either right or left side: you can see your skin wrinkles where your rib cage meets your hip bone in the side you're bending over to. That is your waist.
Once you've tied your ribbon around your waist, ensure it is not tight nor loose. It must be tight enough so it does not move from place but not so tight that your skin gets marked. This ribbon will be the reference to all measurements, so it must not be untied until you finish taking your measurements.
Measurement A - Bust (left picture, yellow line)
Put your measuring tape around your bust. Make sure the tape is parallel to the floor -horizontal- all around your body. You want your tape to pass over the fullest part of your bust.
Measurement B - Underbust (left picture, dark green line)
This time you'll have to measure around your body just under your breasts. Your bra may help you to measure because this line uses to be the lowest elastic of your bra. Make sure your tape keeps parallel to the floor -horizontal- all the way around.
Measurement C - Waist (left picture, red line)
As I said before, your waist is ussually the thinest part of your torso, but if not you can find it by bending over to one side and seeing where your skin wrinkles. Also, as you have your ribbon tied around your waist, you can just place your measuring tape all over the ribbon.
Measurement D - Hip bone (left picture, dark blue line)
Place your measuring tape all around your body not where your hip bones start but lower, where they are perpendicular to the floor. You can touch them yourself, you'll see there's a place on your hip bones that is curved -just below your waist- and another place that runs straight down for a while. It's usually 7 cm or 3 inches below the waist line. That place is the one you'll have to put your measuring tape on and all around that part of your body. Make sure your tape is horizontal all the way around so it's equally distant to the waist tape at every point. Also remember to mark your skin at that point with a pen or a small piece of adhesive tape to help you when measuring H.
Measurement E - Hips (left picture, pink line)
I want you to measure 13 cm or 5 inches below your waist line. As always, place your tape all around and in a perfectly horizontal position. If you want your corset to be lower than that at som point, you can take an extra measurement we may call E* or Bottom below this one -remember to note down the distance between this new measurement and your waist. In anyway don't forget to note every single measurement. Also remember to mark your skin at those points with a pen or a small piece of adhesive tape to help you when measuring I.
Measurement F - Underbust to waist (right picture, light green line)
This is a vertical measurement. You'll have to measure the distance between your underbust line and your waist. When measuring vertically, it's very tempty to bend over to see yourself. Please try not to do this. You can use a mirror to help you to see you're doing well if you're measuring yourself.
Measurement G - Bust to waist (right picture, purple line)
This is a vertical measurement. You'll have to measure the distance between your nipple and your waist. When measuring vertically, it's very tempty to bend over to see yourself. Please try not to do this. You can use a mirror to help you to see you're doing well if you're measuring yourself.
Measurement H - Hip bones to waist (right picture, brown line)
This is a vertical measurement. You'll have to measure the distance between the mark you made when measuring your hip bones contour and your waist. When measuring vertically, it's very tempty to bend over to see yourself. Please try not to do this. You can use a mirror to help you to see you're doing well if you're measuring yourself.
Measurement I - Hips to waist (right picture, light blue line)
This is a vertical measurement. You'll have to measure the distance between the mark you made when measuring your hips -and bottom when needed- contour and your waist. When measuring vertically, it's very tempty to bend over to see yourself. Please try not to do this. You can use a mirror to help you to see you're doing well if you're measuring yourself.
Measurement J - Nipple to nipple (right picture, fuchsia line)
This is an horizontal measurement, but not a contour. I just want you to measure the distance between your nipples horizontally across your chest.
Measurement K - Waist length (right picture, medium green line)
This vertical measurement is not necesssary unless your corset design includes sleeves, straps, collar, etc. You can take it at the same time of F and G. You'll have to find yout neck base, which is more or less in the middle of your trapezius muscle. Please remember you'll have to take this measure twice, one at thr front (crossing one breast from your neck base right down to your waistline taking the fullness into account) and one at the back (this one may be shorter as the breasts usually add volume and we have to be aware of that). The measurement tape must be as vertical as possible, not measuring from the very midpoint at your waist but following an imaginary line form your neck base directly down to your waist line, back and front.
I think these instructions are enough for you to be able to measure your body. Anyway, if you get trouble of have any doubts please feel free to ask me -I'll be pleased to help you.