Man made:

A candle stub.
It is not for catching a spark, but sometimes it is what I use the match or lighter to light first.

Sometimes I can get a match to light but it does not have enough heat to start the fire burning. A candle stub lasts a long time, and gives enough heat to start fine tinder burning even if it is a little damp. Having melted wax to drip into the flame as it starts helps too.

The candle has other uses too.
I grab the cheap table candles when I see them on sale. The tall ones like you would put out for a romantic dinner, not the stubby emergency candles.
One of the dollar stores here sells a box of 24 for a dollar, so about 5 cents each.
I usually break them in half when taking them camping.

Next is whatever liquid fuel you might have. Lighter fluid, naphtha, kerosene (odorless paint thinner is a bit better refined grade of kerosene), alcohol, even gasoline if you are near a vehicle.
Most of these work best if you just drip a bit onto a rag so it burns like a wick.

Magnesium. You usually get this as one of those fire starter blocks. You can find it used in some car parts too.

Steel wool. Fine is better than coarse. Untreated is better than soapy. This stuff burns white hot when it gets going and you blow on it. It will start burning from a spark or a flame. The spark can be electric, like from a car or even a flashlight battery.

Naturals:

Birch Bark, you want the white shreddy layer. The stuff is full of oils and burns with a large smoky black flame. It will burn when soaking wet.
Cherry bark if it is shredded well. It is not as good as birch, but sort of like it.

The small dead twigs off the lower branches of a spruce tree. These are usually bone dry even in the worst weather and are full of resin.

Pine Rosin and the balsam gum from the blisters on a balsam tree. These are both resin and burn with a black smoky flame. Because they are resins they don't get wet.

Fat pine, lightning struck pine, pine knots.. This wood is very full of pitch and burns like oil.

If you look for a large cedar tree you will likely find one side is dry, even after a long rain storm.
The bark can be shredded easily and is very fibrous. It makes good tinder and moderate kindling. If you really shred it up it will even catch a spark for you. It will also wick oils.

Thistle down, Cotton wood down and cat tail fluff are very good but they need to be dry. Cat tail fluff will catch a spark and will burn with a blue flame almost like it was gas.

Birch hoof fungus. Some people call it tinder fungus. It takes a bit of work to prepare and is just for catching a spark.
You need to skin the outer layer and take the velvety layer from under it. Then you work it in your hands so it feels almost like a piece of felt or soft leather and dry it.
It will catch a flint spark and smolder, so I guess it is not an accelerant. It works like char-cloth.