How can I harden my skin for climbing?

How can I harden my skin for climbing?
How to Take Care of Calluses & Prevent Flappers So You Can Spend More Time Climbing

Wash Your Hands After Climbing. This first technique is simple, yet important.
Apply Climbing Salve or Lotion Before Bed.
File Your Calluses.
Try Different Chalk.
Minimize Exposure to Hot Water.

How to Take Care of Calluses & Prevent Flappers So You Can Spend More Time Climbing
  1. Wash Your Hands After Climbing. This first technique is simple, yet important.
  2. Apply Climbing Salve or Lotion Before Bed.
  3. File Your Calluses.
  4. Try Different Chalk.
  5. Minimize Exposure to Hot Water.