Jelqs howto - tight grip at the base

I have a questions for the Jelq gurus, as far as I got to understand, for my needs that is length more than girth, the best would be to Jelq semi erect or rather less than that and to pull to stretch the tendons at the same time, what I am trying to figure it out is if am performing it correctly or not.
I am not holding tight at the base but this way I allow the blood to flow away from the penis, this is wrong, right?
I usually allow between 2-3 seconds every movement from base to head, is this right?
I don’t allow full erection at all but after an x number of moves, given am not holding the grip at the base I loose the semi erection (but it becomes nicely full compared to my usual very very very small flaccid).

Where am going wrong?

Thank you

Hold the base tight, push the blood forward to the glans in a 2-3sec motion with 50% erection. Do stretches for length and combine that with jelqs

The thing you hear the most about jelqing for length is: “Jelq downwards and with a low percentage erection”.
>50% Sounds good for that part, but a jelq is about pushing your blood into the penis, if you are just moving your hand up and down with semi-low pressure,
well it sounds like masturbating :)

Try without doing the jelqing motion at first, just try to trap the blood and watch your penis get more and more engorged,
then try doing it while moving your hand forwards towards the glans (not onto the actual glans, maybe .5-1 inch ahead of it).
If it’s uncomfortable, release the pressure a bit, if it hurts - stop.
You should see the penis in front of your hand being a bit more engorged and slightly harder then the rest cause of the blood pushing against every wall.
The trick for some (including me when I first started out, now I can get it more engorged when I need it), is to have something of erotic nature to glance at
when it starts going down a bit, nothing too extreme but just enough to get you that 50% back.

What then about wearing a ring, would it somehow help?