Some kits include aluminium foil, with one use being to fold into pans to hold water. Is that really practical? What's the best way of doing it? I did a search and found some general Origami links, including these:

• Box 1 This seemed to give the best size, and it starts from a rectangular sheet.
• Box 2 This is another good size, but it requires a square sheet to start with which I see as a disadvantage.
• Box 3 This is another rectangular one, simple but a bit long and shallow.
  

None of them were designed for survival. Also none of them have lids. Water heats much quicker if the pan has a lid. I have made them from paper but I've not tried foil yet, nor have I tested to see whether they are suitable for boiling water. I figured I was probably repeating research that other people have already done, so I should ask. And it looks like something that you need to learn and practice before you need to do it in the wild. If it works, it seems to me that if you can make a fire and boil water, you don't really need water purification tablets. Anyway comments and experience welcomed.

PS This is my first post, but I've been reading here for a while. I live and work in urban UK.