3 strips of friendly plastic, rolling pin or tube, strong scissors, cooking oil, small towel, strong tin foil, pokey tool or similar, heat source, heat gun, thermometer
You can simply have a pan on the gas or the electric hob. If you have the choice I would recommend the hairdryer style heat gun opposed to the other type. If you only have the other type, it's not a problem, but just keep in mind it gets hotter quicker.
Cut some strips off your plastic in differing widths.
Arrange them in a pleasing order.
Taking the opposite ends you are going to 'tack them together using the hot water.
Place the opposite ends in the water for about 10 seconds.
Bring them out and push them together as above.
They should look like this. They won't feel that stable, as you've only attached them together at each end.
Carry on with the pairs tacking them together as above.
Once they are done, take 2 sets of 2 and tack them together using the same process. So above I have tacked a 2 and a 2 and a 2 and a 2 and a single piece.
I then took the 2 pieces above and tacked them together, so now I have a full strip.
Place the full strip on a piece of tin foil.
After about 10 - 15 seconds, push the tin foil in the water and the strip should submerge itself. Leave in for about 20 - 25 seconds.
You can tell if the plastic has melted enough as when you pull it out it will 'bend' on the foil. If it does not bend, it needs to stay in longer.
Once out of the water, rub a tiny bit of household cooking oil on your finger. Rub it over the creases. This will smooth it and fill in any gaps without leaving your finger prints on the plastic.
Take a small rolling pin / tube and roll once over the strip.
Then place in cold water to cool.
After 20 seconds pull it out of the water and dry it off. The tin foil can be used again and again and again.
Take your strip and cut thinner strips off in different widths again, this time length ways as shown above.
Mix the strips until you are happy with the way they look the same as above.
Using the exact same process, 'tack' the first 2 pieces together and so on
until all 5 strips are tacked together.
Dunk in the hot water again, exactly the same as you did when making the first strip.
Pull it out the hot water, put some cooking oil on your finger, rub along the joins.
Roll once with your rolling pin or tube.
Dunk in the cold water to cool for about 20 seconds.
Dry off on the towel.
And this is your piece of piecework friendly plastic.
The piecework technique was founded by Liz Welch and I strongly recommend that you check out both her blog and her DVD, 'Bend it, shape it'. Without it this tutorial would not have been possible.