The shape of the saddle is designed to match the type of riding you do. By this we mean where you ride most often – town, commuting, bike path/trails, mountain bike trails, touring, or road riding. For example, a pear shaped saddle has more width at the rear of the saddle giving optimal support directly under the sit bones for the upright town rider. Contrast this with a T shaped saddle. Mid to narrow rear width which quickly thins to the front section, for a higher intensity ride that supports repetitive pedalling and will eliminate the likelihood of chafing.
The padding and cushioning should then match to the time spent on the bike – Casual (usually under 1hr), Fitness (usually 1-3hrs, 2-4x/wk) or Consistent (usually 1-4hrs most days). It will also be influenced by how regularly it will be used – 1/2 times a week versus most days. All year round, all types of weather versus warm weather riding.
Choose a saddle that reflects the type of riding you do most often. For big days or special trips add endurance padding in the form of a chamois (see the full range of stories on Padded Bike Pants/Underwear for Women) and/or add a gel seat cover.