For best results, take measurements over your underwear.
Bust: Measure under your arms, around the fullest part of your chest.
Waist: Measure around your natural waistline, keeping the tape a bit loose.
Hip: Measure around the fullest part of your body at the top of your legs.
Inseam: Using pants that fit well, measure the crotch seam to the bottom of the leg.
Sleeve: Measure from the center of your back to your wrist with arms held out.