CHEST
Wrap the measuring tape under your arms, around the fullest part of your chest and shoulder blades. Keep the tape snug, but not too tight. 

WAIST
Find the narrowest part of your torso, usually between your chest and hips. Wrap the measuring tape around this area, without pulling too tight, to get your waist measurement. 

HIPS
Stand with your feet together. Measure the circumference around the widest part of your hips and buttocks. 

ARM
Raise your arm slightly and bend it a bit. Measure from the base of your neck, over the shoulder, down the outside of your arm, to the wrist bone.