So, here's my story and how I do it, johnnyboyx4.
I also spent the first two weeks figuring out the device and how to best use it. What I learned is that all of the foam stuff is useless to me. The round ones aren't stretchy enough to fit my penis -- and I stretched them out like in the x-4 tutorial video; I did it with a lot of patience, stretched them slowly and every time I got close to them fitting me they started to tear. I tried to use one that had completely torn through down the middle and just put it on my penis comfortably, with the tear at the bottom where it wouldn't cause me any problems.
That was really only effective when using the comfort straps because there I had the problem of pinching my skin, pulling a bit of it through the hole where the strap goes through -- massive pain, of course.

But then I figured out that the comfort straps don't work best for me, so now I don't need the foam at all.
I am now using only the silicone tube and only at the top holes; I don't need anything around the middle of my penis. I pull the silicone tube through the holes first, then slip my penis into the extender, press it all the way down to the 2100g mark, then slip my glans through the noose, make sure the noose reaches as far down my penis as possible and then I begin to tighten the noose carefully. It starts getting tighter and slip upwards toward the glans as I tighten it. Once it's seated below the glans it's tight enough to hold my penis in place. I then let go of the extender and it starts to lose tension a little bit, so that I am around the 1800g mark. At that point I start tightening the noose more by tightening every side one after the other. So tight that it is a little bit painful; that pain goes away quickly though. If I did everything right it looks like the noose is wrapped all around below the glans, it's tight all the way round to the back.
I then align the x4 so that the screw will turn. I unscrew them simultaneously at both sides until the bar with the ring-marks gets pushed into the bar above it, so that I can barely see the ring-mark at the very bottom -- that's a 2100g stretch. I point the device all the way down at first, because that gives the most stretch.
I should notice that I am uncut, thankfully, so I just pull all the skin through the noose when first fastening it and that protects and insulates the glans. The foreskin will get cold pretty soon, after around 20-30 minutes, but the glans doesn't go blue as quickly and when it does it's not uncomfortable. After an hour or so of course the foreskin and glans are light blueish. That is no problem. It's the way it should be -- I've never heard of anybody avoiding that completely and still getting a stretch, which is the whole point of the device. If you feel absolutely no discomfort at all from the device then you're not doing it right; you're not getting a stretch.
I can go over an hour now with the x4 at 2100g without having to take it off. I only take it off once the glans or the foreskin really hurt. I've experienced zero problems doing it this way. I'm not damaging my penis and everything goes back to normal after a minute or two, especially when I force an erection because that is the quickest way to get good circulation going again. The penis turns blue because the blood that's trapped in it is losing oxygen. Once the "stale" blood can be transported back into the body it gets filled with oxygen again and fresh, oxygen rich blood gets transported into the glans to keep the tissue alive. It's absolutely impossible to "make the glans fall off" because you wouldn't be able to stand the pain that that would cause. I don't see how you could NOT take off the x4 before that happens. Even when you wear it while sleeping the pain will wake you up every time without fail. You'd have to be in a coma for you not to wake up.
There's a couple of other very important things to keep in mind. The scrotum will start to hurt after every 20 minutes or so -- for me at least -- when wearing the x4 in the downward position. There is no way for me to prevent that -- no padding I've tried did the trick, and I know of at least one other user who also came to that conclusion after much trial and error. The only thing that helps is to move the x4 in the upward position for a couple of minutes. Then you can point it downwards again and go for another 20 minutes.
Switching the position regularly is generally a good thing to do because it also seems to help a little bit with the blood buildup in the glans. It won't make it go away; for me I discovered that I could go longer with the x4 on though before the glans/foreskin start to hurt.
Something somebody on here also noticed is that the silicone tubes lose some of their firmness, making it hard to get them to properly keep the penis in place. He said that his tubes had a life expectancy of a month. Me I used the same one for 3 months before noticing that a fresh one worked better for me. It must depend on how many hours you're using it per month.
The BEST thing I found out that nobody on these forums has mentioned is to put talcum on your penis and the silicone tube. This made fastening the noose and keeping the penis in place in process so much easier. Talcum powder is what weightlifters put on their hands before gripping the barbell. It's totally inexpensive. You might already have some at home if you have a baby at home; baby powder is essentially the same thing and should work just as well. It's completely safe to use on your penis as far as I know. Gentlemen have long been using it after baths/showers to soak up rest moisture and to smooth out the skin.
I personally apply the talcum powder to the penis' outer skin AND to the inside of the foreskin and glans. Zero slippage that way.
I definitely advise anybody who's starting out to keep going past the two/three week mark because that's when your penis will have adjusted enough to make using the x4 a breeze. In the beginning I could only wear it for 20 minutes at a time, after a couple of weeks I was up to 30 and now after three months I wear it 80 minutes at a time. At first I could only take 1800g or less. Now I use 2100g every time. So, keep at it, you'll get better at it as time goes by and then you'll see great results.
The last very important thing to consider is you should wear the x4 with as much stretch as you can stand for AS LONG as you can stand without bigger breaks in between. What one member of these forums remarked was that for the first 30 minutes you are stretching tissue that won't increase your erect length, only your flaccid length. If you tire out that tissue then you'll start stretching the part of your penis that really matters. To me that sounds very plausible. I can't imagine short 5 minute bursts to have the same effect on erect length as several 1 hour sessions with little time in between. That's similar to how you need to surpass the 20 minute mark when you are doing endurance training for it to have any effect, and the longer you can keep going in the endurance "zone" the better. And just like lifting heavy weights continuously for an hour will have a completely different effect than doing exercises for 5 minutes spread out on 12 sessions throughout the day, because the intensity of a workout consists of how much weight you lifted in a certain period of time. Lifting 10,000kg in one hour is more intense than lifting the same amount of weight in 12 hours.
And that's all I have to share. Once I figure out something new I'll post it in this thread. Good luck, everybody!
Raphael