To me, do not invest the time to build them until you can work on them daily for at least 10 days in a row. The body is great at healing itself. If you work for 3 days, taking the pain or what ever, then take two days off because you deserve it.

You just lost your 3 days of pain, your body used that time to heal itself. It is something you have to stay at. Not till you have an open wound of course.

After 10 days the pain will lesson, as long as you stay at it. Young calluses will still go soft again with just a couple days off. Most people need at least 60 to 90 days with the calluses on the finger tips before they can take a few days off.

Good calluses and well trimmed fingernails will help a lot.