None of the above for me folks! Sorry, I'm new here as this is my first post. Been a "cracker" for probably over 30 years now I suppose.
Anyway, when I pop my knuckles I twist my finger along a imaginary straight line that runs through the middle of my finger lengthwise. It is pureley a twist motion with no bending at all. Gives me a very satisfying crack and I don't have to twist very far so I never hyperextend the joint.
It has always been my "opinion" that there is no damage done to my joints by cracking them in this manner (twisting). It has always been my goal to find a way to crack my joints in way that does not hyperextend the joint. It is this hyperextension that does the damage to your joint - like pulling your finger all the way back until it pops - your finger wasn't engineered for that!
Try the twisting thing yourself - my guess is that you will like it. I do my knees and elbows the same way.