Firstly you want to get your different coloured bags, you can get lots of different colours so go and experiment different shops, you need to cut them all into little squares. I fold mine up and cut the sides, tops and bottoms and then you can cut them into squares quickly and easily
Next you want to get your zip lock bag and stuff a towel inside it, this is so that when you iron on top of it, the heat will not melt the two sides together
Next you want to get your pieces of plastic bag and place them on the bag, layering them as you go along.
Now you want to get your greaseproof paper and put that over the plastic bags, now iron over it. You need to have the iron on the highest setting and it will only take seconds. Keep placing on the plastic and ironing over it.
Your bag is now done, I found a bag that had very small letters on it so I added my name to it :D