The two most important things to know about your army are the miniatures used in your army and what combat focus you want your army to have on the battlefield. Find out what type of setting the campaign organizer plans to run and what kinds of armies he or she intends to allow. Then start filling in the details. There are several ways to approach this.
You can choose the traits you want, spend your army points, and work out a army concept that fits the traits. A good army is much more than a collection of traits, but choosing a group of unifying traits can be a great inspiration.
You might instead decide on your army’s defining qualities first, such as your national history, miniature appearances, and species. Spend your points on attributes, traits, tactics, and command benefits that go with these qualities.
Finally, you might find it helpful to answer some basic questions about your army, using the answers to develop a biography before you spend any points. For example:
• Where was your army's nation born and how did it develop?
• Who are, or were, your nation's neighbors? Has your nation conquered their neighbors? If not, are they allies or vassals? If so, does your nation get along with them?
• Who are his friends? His enemies? His closest professional associates?
• What were the most important moments of his life?
• What are his motivations? Plans for the future?
You can answer such questions in your head, on paper, or in an interview with the GM. You can even discuss them with the other players (but you will want to keep some secrets, even from your friends). Or you might prefer to answer them by writing a life history.