I think he is referring to a Yukon Pack. If so, then usually you would
use a tarp, maybe they were just practicing with blankets. If you want
to tie one up, just spread the tarp on the ground, or blanket, and tightly
fold it over the contents to make sure it keeps water out. Then,take
a piece of rope and put a loop in the end.
Since you are not putting any weight on the line, any old
knot will do. So, start wrapping the pack from the bottom and
after every pass around slip the rope around itself to keep it
in place. When you get to the top, go ahead and start wrapping
it around the top and bottom. Finish with a trucker's hitch
to tighten it down. Of course this is the simplest way to do
it, you can get into making a frame out of wood and
a lot of other stuff that would create a more comfortable
pack. Then, you need straps.
So, just find a good place to attach rope or
webbing and put them on. Again, you can make
them more comfortable with some foam or other
kind of padding.
Well, I either just wasted a bunch of time
to write this up or helped you out a good bit.
Anyway if you did not know what a Yukon Pack
was before, I am sure you do now, or at least
mildy what one is. Damian