If you take your time you can just light it with leaves, fine twigs etc, then add thicker sticks etc through the top.
However, since finding out about B&Q Fire Lighting Gel, I squirt a little of that on some twigs (it's a thick, white gel), and then just light it. It's a guaranteed flame in seconds, so extremely easy. Once the twigs have started burning, I add some more through the top for to get a big fire inside.
A lot of people use half a fire lighter to get the flames going properly, which I'd do if I don't have the gel with me.
Oh, and yes, we just pick up whatever is around. I also use plain white paper plates when camping, so for the coffee water after dinner, I roll the dinner plates up and add it through the top - great flames, and means less to throw away.