Japanese Cat Plaid Fake Two-Piece Sweatshirt

Bust: Place one end of the tape measure at the fullest part of your bust, wrap it around (under your armpits, around your shoulder blades, and back to the front) to get the measurement.

Sleeve length:  Then start at the middle of the back of your neck and measure to your shoulder, down your arm to the elbow, and then on to the wrist.

Waist: Measure the circumference of your waist. Use the tape to circle your waist (sort of like a belt would) at your natural waistline, which is located above your belly button and below your rib cage.

Hip: Measure the circumference of your hips. Start at one hip and wrap the tape measure around your rear, around the other hip, and back to where you started.

Thigh: Measure the circumference of the fullest part of your thigh. Wrap the tape measure around your thigh from front to back and then around to the front. 

Once you have your measurements write them down for future use when buying online on any webstore. It actually sounds much more grief than it is and should only take a few minutes. ^_^