ngolimit I have the same problem as you in regards to slipping, it is indeed very fustrating and deterring to keep doing PE. I also can feel the hand slipping and putting pressure on the glans even if the foreskin is retracted.
Take this diagram of the penis as an example , see the end of the red just before the glans. What you need to do is visualize this and envision that you are gripping this part of the penis. Feel around for it and you will notice that you can grab onto this part and it will slip between your grip if you squeeze it a few times. What I do is grip this area softly and feel around for this part of the tunica, once you have a grip on it, ‘slowly’ begin to squeeze to get a good grip on it. If you do it too quickly it will sleep and your grip will be in between the end and the glans.
While you are slowly squeezing use the other hand to keep the foreskin retracted and you will notice the red area will be squeezed between your grip and when you begin to ease into the stretch, the foreskin will stay will stay bunched up and not stretch. If your foreskin stretches and you feel pressure on the glans then most likely you didnt do it correctly. Keep trying until it works, go slowly and I use a overhand OK-grip which i find to be more comfortable. You can try the gripping techniques in this thread until you find that you get the hang of them as they are quite “handy” haha. It takes a bit of practice but take it slowly.
If you are confused with anything I said and need better explaining, just ask me what I meant etc… :D
3/02/2019 - BPEL 6.5", MSEG 5.5"
BPEL 6.5” to 9.0" 8% Progress 6.7”
MSEG 5.5” to 6.5" 19.7% Progress 5.71”