Ladies' Shirt

Neck
Wrap the tape around the neck just below the adam's apple. Allow room for one index finger between the tape and the neck. Another method is to use a shirt with a well-fitting collar. Simply, lay the collar out flat and measure from center of collar button to far end of button hole.
Chest
Measure around the fullest part of chest. Keep the tape measure up under the arms and around the shoulder blades

Waist
Measure around the fullest part of your waist.
Hips
Measure around the hips at the widest point

Length
This figure includes the tail length so be careful to measure from the lower back collar band seam all the way down to below the hips.
Width of Shoulder
With your T-shirt on, measure from the back at the end of one shoulder seam to the end of the other shoulder seam.

Sleeve Length
Measure each arm from the top of the shoulder seam down to just below the wrist bone. Arm lengths can differ slightly, so if the right arm measurement isn't the same as the left don't be surprised. To double check your accuracy, measure from the tip of each thumb, up 4 1/2" toward the wrist bone. Make a mark at this point. Now measure from the shoulder seam down to the mark. This technique will reveal the difference in arm lengths.

 
Wrist
Measure around the fullest part of the wrist.