While the application may be the first thing your prospective Commanding Officer sees, the most important part is the character information and the bio itself.  You should spend as much time as necessary to create a realistic character and write a strong biography for that character. When you are done, ask yourself this question “If I were the CO would I want me to become a part of the crew?”  If you answer maybe or no, go back and work a little more.  Most of the CO’s will base their acceptance of the application, and the characters starting rank, on the quality of the application and bio.  It’s worth taking the time to make a good impression.

So, what exactly should a good bio contain?  While each person will have their own style, the following are some of the basic elements that each bio should contain.
1. Your Family.  Believe it or not, this is not a silly addition to the bio.  By knowing who your family is, the members of your crew will be able to understand your character a little more and be able to interact with them even better.  
2. Your Personality Traits.  This should be written as a part of your personnel file, and not in first person.  This is a chance to describe your character from another persons point of view.  The focus should be on how others perceive the character, and how he/she behaves in certain situations.
3. Your Characters Early Years.  Where was he/she born, under what type of conditions, describe their childhood, did they have lots of friends, did they excel in school?  All these are ideas of what to include.
4. Your Characters Academy Years.  When did then enter, how did they perform, what were their areas of focus, did they get into any trouble (not all officers are perfect lol).
5. Your Characters assignments since graduation, if any.  You may prefer to have your character be fresh out of the academy, and that is fine. If so, tell how you ended up on the ship you are applying for. If you are not going to be fresh out of the academy tell about your past experiences serving in Starfleet. Again, remember that your character is not perfect, so give us some of the juicy details about mistakes.
6. What do you hope to accomplish on the ship of your choice?  This may be a little more difficult, but again it gives you and your CO an idea of where you'd like to take your character.

Once you have completed all of this, you should have an excellent bio. Again, proofread your work.  It’s a good idea to write this in a word processing program that does spell check for you.  Again, this helps you make a good impression.