A bit of advice on how measurements should be taken. Some may be easier with help from another person. Measurements should be taken whilst in underwear only, for accuracy.
Bust/chest: measure around the fullest part, ensuring you keep level around the back
Waist: measure one inch above navel level.
Hip: measure around the fullest part
Please note: specific measurements for second-hand clothes are for the actual clothes, not the size of body that may wear them.
Other measurements that are useful for custom-made items:
Underbust: this may be needed for a particularly close-fitting top
Base of neck
Shoulder: measure from the base of the neck (at the side) to where the shoulder curve begins
Neck to waist (both front and back): from the base of the neck (in the middle) to the waistline (one inch above navel level as per earlier measurement) – it may help to tie a string around the waistline for this
Mid shoulder to waist (both front and back): this is helpful for sloping shoulders – the front measurement should go over the bust
Mid shoulder to bustline
Back bustline to waist
Upper arm circumference
Arm length: measure on the outside shoulder to wrist with arm bent (e.g. with hand on hip)
Waistline to hipline: to one side of the front
Waistline to wherever you want the garment to end (e.g. knee, ankle) – both front and back
Inside leg: from crotch to ankle
Outside leg: from waistline to ankle