Personally, I have used the cotton ball/petroleum jelly mix with good success.
I also make tinder using short jute twine lengths soaked in melted paraffin wax
Small bits of bicycle tire innertube
Feather sticks
small pieces of fat wood to really get things burning.
I keep a little bit of everything contained in a waterproof Pelican case.
www.pelican-case.com...
along with a magnesium block, ferro rod and a carbide striker (a repurposed garden tool
sharpener)
www.amazon.com... I just cut down the handle to make it easier to pack. The sparks
literally shower off the ferro rods more than the usual steel strikers or the spine of your knife.