They are super duper easy. I just used a spare scrap of paper - didn't cut it to any particular size (but maybe could have made it a little smaller). All you need to do is roll it into a tube and attach the edges.
Tape together one end. Fill with goodies, then tape together the other end - making sure to squeeze the tube in the opposite direction to before, to make a triangle shaped package (should have taken a photo of that bit - sorry!)
To finish it off, you can use a crimper to add a few crimps to each end of the package, where it has been taped. And there you have it - a childproof package for yummy goodness.