Step one: measurements

I have been so busy at work but I knew that I must get started on the prom dress before it turns into a problem, so the first step is measurements.

I cannot stress how important measurements are.
Good measurements.  Accurate measurements. Many measurements.

This means that you cannot take your own measurements. Get a friend to help.

I thought I should go over the list of measures I take and tell you why they are important.
Wear the undergarments you will normally wear under the clothes to be made.
For men, wear a snug t shirt, non bulky trousers if possible, for women, a camisole and tights/shorts, or non bulky trousers. Take measurements in stocking feet, and measure to the floor where indicated.

Pin a piece of elastic or a twill tape around the waist, this is non-negotiable.

These are the measurements that I take. Measures specifically for women will be noted in red.

height: taken in stocking feet. Useful for comparison with other measures, and in proportional formulas.
weight: useful if sending measurements to someone who hasn't seen you in the flesh
neck: taken close to the base of the neck
bust/chest: taken over the fullest part of the bust, tape level, and for men, make sure  the tape does not    slip down in the back.
ribcage: taken under the bust
waist: for men, at the navel, where the waist tape should sit. For women it is usually slightly above the navel, usually where the torso is the most narrow.
hip: around the fullest part of the hip for men. For women, take an upper hip and full hip measurement.
across front: this is taken horizontally above the fullest part of the bust, from the crease of where the arm joins the body.
bust point to bust point: distance between nipples.
front length: from the base of the throat to the waist tape.
across back: horizontally mid back from the crease of where the arm joins the body.
back length/nape to waist: from the nape of the neck to the waist tape. The nape is the seventh cervical vertebrae and can usually be seen or felt.
nape to back of knee: feel for where the knee bends
nape to floor: in stocking feet
nape to shoulder: feel for the bone in the shoulder socket.
nape to elbow: taken with elbow slightly bent
nape to wrist: over the slightly bent elbow to the wrist bone on pinkie side of wrist
nape to bust point:  generally for women only
nape to waist front straight down over full bust: useful as a balance measurement
nape to CF waist: useful as a balance measurement
shoulder width from neck: from the side of the neck to the bone in the shoulder socket
bicep: at fullest part of arm, flexed
forearm: a few inches below elbow
wrist: around the wrist
waist to knee: measure from the waist tape to the level of the middle of the kneecap
waist to floor/outseam: measure from the waist tape, to the floor in stocking feet
inseam: from crotch to floor in stocking feet
thigh: at fullest point
below knee:  in the hollow below the knee proper
calf: at the fullest point
ankle: around the ankle
girth short: from waist centre front through the legs, to waist at centre back
girth long: from throat, between legs to nape of neck
bra size: useful for determining proportional bust darts

additional:
some tailors will take a measurement from shoulder point to shoulder point, and some take a measurement around the whole body at the shoulder level, so it encompasses the bulk of the arms.
rise: some take it by seating the person on a chair and measuring from waist to the chair seat.
glove size: over the knuckles with the hand clenched
Bowed legs: check for bowed legs or knock knees by asking the person to stand with their feet together, and look. Measure the bow if it is severe.
Stance: best seen in photos but check posture when the person is relaxed, do they stand slumped, or hip forward, or erect?
Seat: do they have a flat, average or full seat? again photos help.


questionable:
any measurement that doesn't have a definable fixed point to start from, such as side length from underarm to waist, or measuring to end at an approximate position such as a side seam.
Measurements such as these cannot be used with any accuracy when drafting or even checking a commercial pattern.

very useful and recommended:
three photos, hopefully in good light face on, in profile and the back.
These are very useful in seeing figuration like shoulder slope, sway back, hip stance......and most helpfully, disproportion. If the person carries a lot of weight a photo helps to determine where their weight is distributed.

I think I remembered them all!
This may seem like a lot of measurements but they all have a function in draftting. You can also use them to check a commercial pattern.
Proper measurements will enable you to get closer to your desired fit right from the start. There will always be tweaking of a pattern but good measurements and the interpretation of the measurements will hopefully eliminate major alterations.