Sorry, I kind of went in overboard mode writing this, I tend to do that too often :/ Some of this may be very helpful, and other parts may be irrelevant to you, but if they are, then they are extremely helpful. Post is based on tons of reading, plus personal experiences with PE. I'll tell you it does work! 1 month = .5 inch length increase!
Everyone is different which is true. Some find it to take a whole year, and others only 3 months. Though I notice many people by month 1 find a .5 increase in length, or by month 3 find a .5-.75ish inch increase in length (when I read many of the success stories). First note, jelqing is considered a girth exercise, but many do see length gains. They suggest going at 50%-75% erect while doing them for peak effectiveness. How to kind of help yourself know you're there is to be just quite not exactly hard enough to penetrate, but when you kegal see/feel the blood expand. Also, I suggest doing anywhere between 3-5 second strokes (2 second strokes here and there won't be a problem during your exercise) because I believe 3-5 second strokes will be the most effective for gains, and doing 3-5 second strokes will also prevent injuries. Also, be sure to have good form, (not go to fast per stroke like that one PEgym video guy does it) and if you are just starting off do at least the first two sessions 25-50 strokes depending if it is hurting or not, and have a very light grip for the first 3 sessions or so, not super light just a bit harder than masturbation. Then increase the grip after the first week, but not anything too hard at all.) I went too hard one day in the beginning and it made it harder to get erections (could have also been due to lack of sleep though, and constant masturbation those 3 days...) I fixed my erection quality back up after the third day deciding to try PE again and did it very light the next 3 sessions and 2 hours after the first session back at PE my EQ was back to 100% and everything was perfect) I also suggest you do 2 days of your routine in a row, then 1 day rest so your wiener can rest and rejuvenate and grow.
Well, my first month of mostly jeqling, (2 days on, 1 day off), and slight stretching in only some of the sessions (especially towards the end of the month) gained me a solid .45-.5 inches in length, and a permanent .15 (lost like .2 of the girth gains after stopping for 7 days after finishing that full month, but kept all the length gains.) I started off the first week doing no more than 50 jelqs, second week basically the same and did stretches two times those first two weeks. Third week I stopped counting and did 5 minutes jelqing sessions, and midway in it 10 minute jeqling sessions, then fourth week 10 minute jelqing sessions with 5 minutes manual stretches before the jelqs.
Okay, look at your wiener right now when erect and check if your head has that "non-shiny-ish, deflated-ish, not blood filled look to it." if that is your case, smile (I guess you can celebrate a bit, or not? Depends how you look at it haha) You will definitely get some very quick length gains from jelqing because that is how my head glands looked before jelqing. After the first week or two you will notice it to be much more "blood filled (not trying to sound weird)" and by the end of month one it will look tons better and therefore help give a large increase in length. Keep in mind, i half azzed my first two weeks not believing PE to work, so if I did better form in the exercises I would have gained much better. If this 'gland head thing' reflects to you, it will also make condoms more snug at your head which is nice. Also note, it wasn't that I couldn't get 100% erections, it's just before PE even when I did get 100% erections my head gland would just not fill up very much for some reason. But after 2 weeks, especially after 1 month of PE, it now is wider, longer, and just larger and better looking.
I suggest (especially if you haven't tried PE yet) to start off your first couple sessions with a light 25-50 jelqs. Then after that first rest day, do 50-75 light-ish jelqs, then fourth session 75 lighti-ish jelqs (3-5 second strokes). Then your second rest day will come. After that I suggest, you add 2-3 minute manual stretches to your routine for your next 2 sessions. (straight, up, down, left, right (look at a video of it). Don't pull hard at all especially these first two sessions of starting stretches. Then after your third rest day, do 5 minute manual stretches, and 5-10 jelqs (10 minutes if you feel you are able to). I only say start off slow because when I first started PE I sometimes would jump in too hard/too many I guess and I would feel really sore or injury like feels.) After the third week of PE my wiener got used to it and I can do harder jelqs and very long sessions and everything is just really okay now. Just the beginning was a time were I would kind of feel injuries when I went crazy a couple sessions and did too much. Now I can do 15 minute stretch sessions, with 3 sets of 30 second Ulis, and 20 minute jelqs all in one session with no pain, only gains.
One more note that could be helpful that I recently read on this forum. During stretches, rather than pulling hard for shorter duration, pull it softer for longer duration, it is supposed to help gains faster or something, I don't feel like explaining all the technicality they had behind it haha. Well good luck!