Measure against your body rather than over your clothes at it will give a more accurate result.
1. Bust:
Measure under the arms at the fullest part around the bust horizontally
2. Waist:
Measure around the natural waistline
3. Hips:
With the feet together measure around fullest part
4. Inside leg:
In bare feet take the measurement from the top of the inside leg and measure down the inside leg to the floor
5. Height:
With bare feet together measure from the top of the head to the floor