Choose a smooth chamois. Look for shorts with a one-piece liner or one that’s sewn with flat seams. It may take experimenting with shorts brands or chamois types to find the model that works best. Women often do better with shorts designed specifically for their anatomy and that have a liner with no center seam. See the  article, "How to Choose Cycling Shorts."
 

Select a supportive seat. Saddle choice is crucial. Excessively wide saddles rub your inner thighs. Narrow saddles don’t provide enough support for your sit bones -- your weight is borne by soft tissue that can quickly become bruised and irritated. Thickly padded saddles can press upward between your sit bones, causing uncomfortable numbing pressure. The best choice for any individual rider can only be found through trial and error. Hopefully, your bike shop will have a saddle test-ride program or liberal trade-in policy.  "How to Find a Safe Saddle."
  

Lube to reduce friction. To prevent the chamois from abrading skin, apply lubrication before each ride. Try a commercial product such as Chamois BUTT’r or Bag Balm, or simply a light coating of petroleum jelly. Apply a dab the size of a nickel to your crotch before putting on your shorts.
 

Keep clean. Always wear clean shorts for each ride. If you seem susceptible to saddle sores, you may find it helpful to wash your crotch with antibacterial soap and warm water before lubing up. Dry your skin well first.
 

Strip quick. After a ride, get out of your sweaty, germy shorts as soon as possible. The environment down there breeds bacteria and encourages them to enter abraded skin. Then shower or clean up with soap and water. Dry well and put on loose-fitting clothing that allows your skin to breathe. For underwear, try boxer shorts. The tight leg bands of briefs cut across the junction of your glutes and hamstrings, right where many saddle sores develop.
 

Sleep in the buff. It keeps your crotch dry and free of clothing contact for as long as you’re in bed.

If You Get a Saddle Sore

Medicate it. Besides keeping it clean, treat it with an over-the-counter acne gel containing 10% benzoyl peroxide. Perhaps even more effective is the topical prescription product called Emgel (erythromycin). If a sore is getting out of control, ask your doctor about a course of oral antibiotics.