armgrab - viewer's hands contact with upper arm/lower shoulder
shouldergrab (less common) - viewer's hands contact with shoulders
overshoulder (rare) - viewer's hands go over shoulders
restingonhands (rare) - viewer's hands are on the ground to the sides of subject's head
wristgrab - hands contact with wrists
wristpull - viewer's hands pulling wrists, subject arms extended downward. Might come out janky, but if it works sometimes, it can be improved for later versions.
wristgrabmid (less common) - subject's arms down, forearms and hands raised next to head. Might come out janky, but if it works sometimes, it can be improved for later versions.
overheadgrab (less common) - subject's hands above head. Might come out janky, but if it works sometimes, it can be improved for later versions.
Combinations - preliminary findings
"overheadgrab" seems best used alone, with prompts that will place the subject's arms above their head lying on the ground.
"overshoulder" might work with "armgrab", but afaik is harmless and often just doesn't do much. You can try it alone, but it is a little weak overall and "armgrab, overshoulder" + randomness might even have better odds.
"wristpull, wristgrab" seems fine and can work with POV missionary sex, though it can take a few tries. Works more often without that complication.
"wristgrabmid" seems best alone. I have had a hard time getting the subject's hands in place, but "waving both hands, hands to the side of head" is a hack that works, but as a side effect, puts the subject's hands in waving position. If you have a workflow that can do inpainting, you could try two steps here.
Still haven't tested "restingonhands", but this one occasionally happens on its own when other tags fail a grapple check.
Weights
It's formatted as a pose/concept category, but it does seem stylistically opinionated. I would like to get images that look substantially different while getting the one detail of the pose right, but it's not there yet. Abstracting what you really want while being compositionally fluid seems to be a hard trick.
I tend to use between 0.4 and 0.8, but it's not really science. You can try increasing until one or two grapples connect out of four, or bringing it down instead.