My favorite commercial tinder is Tinder Quick. Recently I have been trying to carry less gear so I carry lots of stuff with multiple uses and I have no redundancy. With that in mind what I have found to work really well from even a small spark is the little 1"x1" alcohol pads that come in most first aid kits and can be bought at the drug store in boxes of 100 or more. They burn plenty long enough for me to light a fire with under almost any conditions and the are also effective for cleaning cuts and scrapes.