Elbow and Knee Joint Tightening Help?
 

So lately I've been sort of "dabbling" in the process of fixing the hips and waists of some of my "Floppier-jointed" figures (looking at you DCUC Doomsday) with the easy "rubber-band trick" (simply wrapping a taught clear rubber band around the waist to tighten up the joint.)

But then I recently purchased the new Jazwares Scorpion and Sub-Zero, as well as the new MU Skaar. All very cool figures with the same problems, the elbows and knees joints are loose and floppy and don't seem to hold any sort of pose very well. I've searched on other sites for a solution to this specific problem and haven't been able to find much besides the "super glue" trick (which I've tried and cannot get to work) and the "craft-paper" trick, which I cannot seem to find a detailed explanation of anywhere. So can anyone help me?

In summary I need help tightening up the elbow and knee joints of my:...
Jazwares Scorpion and Sub-zero
MU Skaar
DCUC Skallox
NECA Sammael

I would greatly appreciate any step by step help or tips on how to "tighten up" the floppy joints on these figures. :)