I much prefer straps over bungees.

For straps I think most of the ones mentioned are overkill. I prefer Coughlin's sleeping bag straps. They are 3/4" wide with a plastic buckle. Also they are poly rather than nylon which is good because nylon stretches and gets looser when wet. They come in a pack of two, sometimes for less than $2 for two straps.

I own better more expensive straps that I use for other things than touring, but find the poly sleeping bag straps perfect for touring.