This tutorial includes templates which will help you with the sizes and shapes. Click on the 'Templates' button below to download them. 

6.

Put the part flat on the board again. Leave it to dry for a few minutes. It should be quite firm before you trim it*.

Cut off the top part. Use a sharp, clean and dry scalpel**. Make the cut at an angle - see next photo. You can use the template as a guide (4) - it will show you where to start and end the cut to get the correct angle.

* If you make the cut when the paste is still soft, the body will lose its shape and you will not get a clean cut.

** If the scalpel is not sharp, clean and dry it will pull the paste down and you won’t get a clean cut.