Well, as any other programmer out there all my timings should be multiplied by 3 to get it right.
I wanted to build a plaster-pasterboard wall which will hold a glass wool layer in the kitchen near air trunk for the better sound insulation. Also wanted to setup a kitchen door and build a wall (from the same materials) on top of it up to the ceiling.

And I only finished (even not completely) the main sound proofing wall (which will help a bit, but without door it is unlikely to be very useful) because I did not get enough screws.

So, here is the plot

->

Each of four plates weights about 20 kg, its dimension is 120x110 sm, and two of them are being held by only 3 screws instead of 6.

I fucked myself again was a little bit tired doing it with two hands only. Definitely for anything which has more than 30x30 sm in dimension and its weight is more than several kilogramms pair of hands is not enough. I want another couple of my own.
For this task I even used a head. By the direct meaning of this phrase - I used either skull or jaw to hold some stuff while hands usually held a plate or a glass wool.

Especially fun it becomes when I drop something or forget to take - hands fix the plate attached to the wall (it is rather resilient 20kgs because of glass wool, which should be complressed), head holds screws and foot tries to get a screwdriver or other instrument. Actually it is fun only when it is over :)

I recall what I used when build a big hinged ceiling (its total weight is more than 100 kg) - ropes, own back, special holds... Well, I enjoy the result, hope my sound insulation will be good as well.