Measuring your waist is the first step to get your ideal waist size. By the way, the ideal waist size for women is 32 inch and 35 for men.
First of all take a deep breath and suck your stomach in, then measure your waist size at the belly button. According to Dr. Oz you would measure your waist size that way, but there are other people who have different opinions.
However, the rule that 32 inch is the perfect waist size applies to that way of waist size measurement. You can’t suck in your omentum, so this method should be working just fine. (The omentum is the place where you store all your fats)
Sidenote: If you own the book YOU: On a diet, you’ll find the information about waist measurement on page 11.