Self-bondage Challenge
Now take your 2-meter soft rope, hold the two ends together, and lift it off the ground to form a "U" shape. Then put the chain between the handcuffs in the middle of the "U", so that one cuff hangs out on either side. Tie the rope around the handcuff-chain in a half-knot, so that the handcuffs are stuck in the middle of the rope.
Now turn it upside down, holding the handcuffs with one hand (though not locking them on to anything yet) and letting the ropes dangle. With your other hand, tuck one end of the rope between yourself and your belt, so that your belt is now in the middle of the now-upside-down "U" shape formed by the two sides of the rope. Now pull the ends of the rope down, until the knot and the handcuffs are sitting directly on top of your belt. When you pull down on the ropes, you should be able to let go of the handcuffs, and the rope should keep them in place on top of your belt. Now tie the ropes in another half-knot to keep everything in place.
Just to make it more secure, bring the two rope ends up on either side of your belt and handcuffs, and tie another half-knot on the top of your handcuffs, before brining them back down on either side of the handcuffs again. Finally, slide the rope and handcuffs along your belt, to behind your back. The rope and handcuffs should now be directly behind your spine, while your belt buckle remains just below your belly button.
Now bring the two rope-ends between your legs and up to your belt buckle. Men, you will want to bring up the sides of the rope up on either side of your cock and balls. For everyone, this will give you a bit of a wedgie, but trust me, that will be the least of your problems soon enough. Now tie the ends of a rope, in a full and secure knot, to the belt buckle. Don't pull the rope too tight before doing so, as I don't intend for this to be a painful crotch rope. It just has to be snug and secure enough so you cannot escape.
The handcuffs are still free to slide around the belt, so you need to make sure that the rope between your legs is tight enough to keep the handcuffs away from the belt buckle. Test this by attempting to slide the handcuffs along the belt towards the buckle, close enough so that a handcuffed person would be able to unbuckle the belt. If you can do so, then the rope between your legs is not tight enough. Untie the rope at your belt buckle, and re-tie it tighter, until you cannot slide the handcuffs close enough to reach your belt buckle. Once this is proven, move the buckle and handcuffs back into position. The buckle should be directly in front of you, while the handcuffs are directly behind you.