It depends :

A ferrocerium rod will produce more, hotter, larger sparks than a traditional flint and steel and with care you can shave off a small pile of material from the rod without sparking it which can act as an igniter.

Ideally you should carry a reasonable quantity of tinder with you in a waterproof container like a tobacco tin, this means that you will always have the means to reliably create a flame. This should be topped up as you go. Obviously once you have got a fire lit you have the means to dry more tinder to replenish what you have used.

A good weather resistant tinder is cotton wool impregnated with Vaseline tampons are also good as they are very compact and are available individually wrapped.

A good habit is to collect any good tinder you find on the trail as you go if it is a bit damp you can keep it in an inside pocket and dry it out with your body heat throughout the day.

There are plenty of good sources of natural tinder, some work well as they are, others may need a bit of preparation. In Europe bracket fungus has along history as a tinder and many other fungi and lichens will also work well when dry. Partially rotted wood from resinous woods can also be good and pine sap can be an effective accelerant if not an actual tinder per-se.

Often natural tinder will need a bit of preparation. Usually it is enough to scrape the surface with a knife or rock to produce a fine powder which will catch a spark more easily.

You may also find that with natural tinder some is good at catching spark and you then need something a bit more fibrous to get a flame from the resulting ember.

You can also make good tinder from char-cloth this is obtained by partially burning cotton (or similar plant based textiles). @You can make this is bulk by heating cotton in a partially sealed container or just carry a roll (like a bandage) and it should charr itself as you use it.

Obviously a lot depends on the environment you are in and it is well worth experimenting with anything which looks likely before you really need it.

It depends :

A ferrocerium rod will produce more, hotter, larger sparks than a traditional flint and steel and with care you can shave off a small pile of material from the rod without sparking it which can act as an igniter.

Ideally you should carry a reasonable quantity of tinder with you in a waterproof container like a tobacco tin, this means that you will always have the means to reliably create a flame. This should be topped up as you go. Obviously once you have got a fire lit you have the means to dry more tinder to replenish what you have used. Indeed there was a time in teh not too distant past when tinder box was the normal way of making fire.

A good weather resistant tinder is cotton wool impregnated with Vaseline, tampons are also good as they are very compact and are available individually wrapped.

A good habit is to collect any good tinder you find on the trail as you go if it is a bit damp you can keep it in an inside pocket and dry it out with your body heat throughout the day.

There are plenty of good sources of natural tinder, some work well as they are, others may need a bit of preparation. In Europe bracket fungus has along history as a tinder and many other fungi and lichens will also work well when dry. Partially rotted wood from resinous woods can also be good and pine sap can be an effective accelerant if not an actual tinder per-se.

Often natural tinder will need a bit of preparation. Usually it is enough to scrape the surface with a knife or rock to produce a fine powder which will catch a spark more easily.

You may also find that with natural tinder some is good at catching spark and you then need something a bit more fibrous to get a flame from the resulting ember.

You can also make good tinder from char-cloth this is obtained by partially burning cotton (or similar plant based textiles). You can make this in bulk by heating cotton in a partially sealed container or just carry a roll (like a bandage) and it should charr itself as you use it.

Obviously a lot depends on the environment you are in and it is well worth experimenting with anything which looks likely before you really need it.