My Hennessy has a loop for a peak bag, so I took a smallish light stuff sack and sewed a mitten hook to the bottom with a button on the inside for reinforcement. Of course it can still be used as a stuff sack until camped. It is a good size for suspension hardware or a small tarp.
If you don't have a loop in the peak, a bag could be hung from a prussik loop at the end of the ridge line.
I wanted something to hold my inflatable pillow or a book. The ridge line pocket isn't big enough for a book and the pillow is in the way getting in. Shug has a video showing a larger one where he stows extra clothing for cold nights.