Remember that the financials should support the text of your business plan, help you to run your business better, and help you to get financing, if needed.

The trap many people fall into in creating financials however is to be hopelessly buried in small details such as creating long lists of office supplies or getting frustrated trying to figure out the latest rules on depreciating assets. Instead, I suggest you make your best quick estimate on less important smaller numbers and give more thought to the numbers that really matter. Of course, you can always go back later and do a more careful estimate on any particular entry, if you want to.

Examples of some of the numbers that really matter (and that potential financiers are likely to ask you about) are your sales projection, the average number of days you expect to get paid, your profit margins, and when and how you are going to repay any debt.