Boy and Girl Scouts are really good at building fires on the fly, and while theirs is a surefire method of fire-building, lots of other methods work equally well. I am going to describe a few different ways to get the job done, and you can then choose what works best for you, or even develop your own unique method.
Until just a short while ago, I always used a technique that is very similar to the Boy/Girl Scout method: dry kindling on the bottom in a teepee fashion, paper under and around the kindling, then larger and larger pieces of wood until you have the size of fire you want. Nowadays, I tend to use several different methods depending on what I am doing and whether I am building a fire in my large wood burner, in one of my smaller units, or in the fireplace.