Tip one: Don't cheat. They have many years of data. Knowing your income (W-2 forms), your working history, and number of people in the family etc information, they know the range of $$ you should have. Outliers without special circumstances could be audited.
Tip two: Start it early. Many schools have their own supplimental questions and you may need time to get all the informations. Some schools, for example, will ask what type of cars do you have, when did you buy them and how much you pay. If you just paid $80K cash for an S430, you would probably be asked to pay a lot tuition.
Tip three: Make sure you use the last section to list all your special circumstances. The more specific, the better. The best way is to provide a number, such as "we spent approximately $5000 a year for this so and so".
We did not know this point in our first round. Only after we received the FA package we realized we could not afford the bill. When we talked to schools about the special circumstances then, they said they have limited reserve to make a minor adjustment.
Tip four: Think ahead: if you know now something big is going to happen next year, disclose it now. For example, if a large portion of your pay is bonus based on company performance and the company already announced that there will not be one next year. You want to let the school know.
Basically, each school has a budget for FA. They might give out 95% with 5% as reserve. So their hands are tight after the first round. You want to get your slice of pie from the first 95% of the budget.
Good news for those low income families like ours. The earning opportunities for students at top school on campus are very good. To make $6~10K in one summer or $2K per quater is not that difficult. So, as long as you could getby the 1st year, you will be o.k.
Best of luck.
PS. not bricks please. I am trying to help. out.