One of the most important things to remember is to lightly spray your chipboard with water. Make sure not to do it to heavily or it will make the chipboard very weak. Hold the die upright and give it a couple of hits with the mallet. I tend to lean my very slightly as I hit it with the mallet, that seemed to give a better impression.
Also, this is the second important thing to do, make sure that your dies are kept clean. I use a paper piercer to accomplish this.
I will be posting my first book in a day or two so come back and see what I have created.