Whether you have written a business plan before, or are planning to write your very first one, try to avoid these very common mistakes:
You have to know what your readers (ie: potential investors) will be looking for in a business plan, and then write for those needs. It does not mean inflating data, statistics, or projections, but rather addressing each component of your plan in an honest, realistic, and straightforward manner. It goes without saying that if your readers see blank/missing sections, substandard returns or impractical ideas, they will most likely dismiss your plan with little or no feedback.
Writing section after section before having your strategy firmly established is a little like putting the cart before the horse. You need to ask yourself key tactical questions before writing your plan. You need to understand, for example, if your team is in fact qualified to start a business, how operations can improve, how much technology will be implemented in the first few years, etc. If you have yet to address these issues, you are bound to face countless rewrites.
Plans that describe huge target markets and a multitude of offerings might appear impressive, but could actually work against you. Your plan needs absolute focus, just as potential investors need specifics. They need to see that you understand your market from all angles, and know exactly where they will make the most "bang for their buck".