Step 1: What do you need ?
You need :
1. black bags (4-6 pcs)
2. flip-flops (I'm using my "FAKE CROCS" from Primark for �3 GBP)
(If you are going to buy some, buy bigger one. At least one number or two bigger. I'll explain latter...)
3. some strings (I took it from my old shoes)
4. duct tape
There are other 2 tools, I didn't take the picture, but I used them:
6. long tweezers
7. red "stick" for holding the string
Step 2: The top of the black bags
1. put the duct tape around the top of the black bag. By TOP I mean that part of the black bag, that has the hole :) See picture 1.
2. you should bend the tape on half to create something like tunnel ... (for the string.) picture 2.
3. put another duct tape over the tunnel you just created so, that half of the duct tape touches the tunnel and half the black bag.
The reason, why I created the tunnel is for the string, that will hold the black bags on your legs. If you would just bend the end of the black bag and put tape over it ... the string (by pulling) could damage the bag - and it would not hold together.