A drop or two at each joint. Work hinge a few times. Wipe off any excess.
I have been wondering that also especially during restoration. If you just put a few drops of oil on it when it's installed there really is no way that the oil can lubricate it thoroughly but if you pull the hood rods lube and re-install your good to go. Question is what would be the best lube to put on the rods before re-installation?
The first thing that I do is replace the steel hood hinge rods with stainless steel. Most vendor have them, they don't rust and need no oil.
I found the vendor stainless rods to be too tight a fit. Just can't get them in.