Use a flexible measuring tape
Stand straight with feet together
Wear minimal clothing or fitted clothing
Measure chest around the fullest part
Measure waist at the narrowest part
Measure hips around the widest part
Measure shoulders from edge to edge
Measure inseam from crotch to ankle
Measure sleeve length from shoulder to wrist
Measure neck around the base
Measure height against a wall
Keep the tape level and snug, not tight
Record measurements in inches or centimeters
Recheck each measurement for accuracy