Cuff strategy to maximize longevity of pants
I've never seen the book you mentioned, but it seems to me that maximizing the amount of material in the cuff would maximize how many times you could make repairs.

Assuming that the pants are bought with deliberately too long legs, roll the fabric into the leg space to create an extremely tall invisible cuff.  Pin that cuff in place at a more normal 1/2" to 3/4" height.  This should create the first (most interior) hem.

Now fold the excess fabric from just above the pins and pull it down so that it once again extends out the bottom of the leg opening.  Darn the top of the interior cuff in multiple places to keep your toes from catching it when putting on the pants in the future.  Recover your pins

Next, fold the downward pointing excess fabric (outward this time) to wrap up over the first hem and cover it with another layer of cloth.  This will form an exterior cuff which may still be taller than normal, but will be shorter than the previous interior cuff, because some to the fabric is now trapped inside the pant leg.

If you still have a enough excess height to reach the leg opening again, pin and darn the new cuff at the normal height, then fold the remaining excess fabric outward and roll it downward and then back into the leg opening.  This will form a second interior cuff which you will again need to pin and darn carefully to avoid snagging toes.

If you do not have enough excess height to create a second interior cuff, fold what excess height you have, inward so that it tucks into the newly created exterior cuff.  Pin and darn the top of the exterior cuff at a few points to hold it in place.

Here is a rough diagram of what I am talking about...