Yeah building to a climax is very important and it has awesome effects when it comes to composition. My favorite is when the melody builds with one instruments playing it real soft to an entire symphony blasting it. Like the beginning of Ode to joy. Good stuff! A theory proven by Bach was it's not where you begin that makes the song, it's where you end. Getting to the end is the idea of composition, the route you take to get there is your own style but the end is what defines the song. That's why almost every song ends on the root or tonic. Although this is an idea that is almost lost in modern music. The best way to write a truely unique song is just to write from beginning to end and not care what the structure is, just go with it. Also using variations is a good idea if your songs\ only has 1 or 2 main themes.