
There are several ways to make sure that you will always be able to get a fire going, no matter what may happen (with-in reason!). One thing I always do is take along some water-proof matches in a water-proof container. You can pick up the screw top style for only a couple bucks in any sporting goods store and the added insurance is worth every penny.
You can make your own water-proof matches easily by dipping the heads of STRIKE ANYWHERE* matches into melted paraffin then allowing the wax to set-up. These will take a soaking and still light, even with-out the water-proof holder. *Also known as Lucifer Matches

Having a couple of butane lighters handy is also a good idea. They are inexpensive so having a couple of them around is easy and a good idea in case one of them conks out on you.
If you are out on the trail it is also a good idea to keep a little tinder on you to help get a fire going in case you need to. I like to have a little bit of birch bark in my pack for this job. Birch bark has a high amount of natural oil in it a will burn easily with a hot flame even when damp.
Another good fire starter you can make is by taking cotton cord and cutting it into 1 inch lengths and soaking them in melted wax. (Make sure it is cotton cord) Lay them out to dry and them place them into an empty 35 mm film container. This will hold enough of the "fire sticks" to get quite a few fires going, and it takes up little room in your pack.
Here is a neat idea sent to me by Elliot Cohen.... Take the lint from your clothes dryer and form it into small balls. Then pour melted wax over the lint balls and set aside to dry. When the wax is setup take the lint/wax balls and place them in a water proof container and you have an inexpensive supply of fire starting material. Thanks Elliot!!!! Click Here to visit Elliot's web site!
I use "used" candles when I can, and if I don't have enough of them around I buy large pillar candles at my local dollar tree store. Five or six of them will make quite a few fire starters. The whole process will take several days to complete, and a couple of hours of honest work (much of the couple of days is just waiting for the wood chips to dry), but you can make a lot of these at one time, and it doesn't take a lot longer to make fifty than it does to make five. I store the finished fire starters in a plastic container which I also bought at the dollar tree store. The fire starters burn with a hot, and generous flame, and will last 15 minutes or more. They must be used in an enclosed fire ring, as when they burn down the wax will run out of the cup and pool up, and eventually when it gets hot enough the pooled up wax will ignite. Obviously you don't want this to happen outside of your fire area, so make sure you build your fire in a bit of a depression, or contain the melted wax in some way. I have never had one of these fail to get a fire started!
Another handy item you can make and carry in your pack is a small home-made "sterno" can. Take a small tin can (a tuna fish can works well), roll-up a piece of corrugated cardboard tightly and stuff it into the can. Make sure that the cardboard is just below the rim of the can. Then melt some wax and pour to over the cardboard, making sure the wax gets in-between the spaces in the cardboard. Then take the lid and place it on top, securing in place with tape or a rubber band. This little item will burn for some time and if you wish to put it out, you snuff it out with the lid.