YaWhat ; the thing about extenders is just time and traction. There is no program to follow other than as much time as possible, and with the amount of traction your penis can handle without getting sore, blisters and pain. Do as much as you can each day, and put in rest days if you feel like it or your penis tells you it need a break.
Zilongpro; extend your penis as far as it will go every day. Don’t worry about it being more or less than the erect length, it will eventually ( after some time ) be longer than your erect, but that is a good thing and just show you that gains are on the way.
To both guys - and everyone else too ; be sure to put together the extender in a way that when compressed, the extender is at a length that your glans is almost in front of the cradle ( frontpiece), when the penis is flaccid and stretched, so that the noose is pulling downwards to secure the penis in place, and when releasing the noose will pull forward without trying to pull « through» the glans. In that way you can keep the noose a bit looser and allow for some bloodflow, and you are able to keep longer sessions. I usually keep my extender on for 2-2 1/2 hours per session , but I usually jelq some blood to the glans every 20-30 minutes, and that is possible because I keep the noose loose enough for that. I know it is fun to impress oneself by making the extender as long as possible, ( I know - I used to do that in the beginning, but I found the right way to do it eventually), but that will lead to pain and wanting to stop using it. Good luck guys.