Jelq with back up squeeze
Been doing this for the past few days and it seems to increase pump over a standard jelq. What I do is preform a standard jelq with a overhand ok grip.
As you slowly move the grip down the shaft (if you are using your right hand) take your left hand with thumb on top and index on the bottom , keep it right behind your jelq grip ,actually touching your right hand - slightly squeeze and mash (flatten) the shaft as it comes out from behind your jelq grip.
You can switch right and left hand but it seems easier if I stay with the right hand jelqing with the left hand behind squeezing and flattening. Also Vaseline seems to work better because it slides much easier.
It seems to pump it up big time! , I think the slower the better.