Start by writing a description of your business, including what stage of development it is currently in (conception, start_up, first year, mature, exit) and your plans for growth. Discuss the nature of your business, the main products and services you offer, the market for your products and services, and how and by whom the business is operated.
Do not try to write your business plan in one sitting. As I mentioned in the beginning, for a traditional brick and mortar business, it could take in excess of 100 hours to compile all of the information needed into a comprehensive but yet understandable document. For online businesses, probably not that long. But your final product should be well thought out, well documented and easily understandable.
No matter the economic slump, increasing profits is typically the number one goal of any business. To ensure profitability, a company must demonstrate a competitive advantage over others in its industry, either by cost leadership (same product as competitors, lower price), differentiation (same price, better services), or focusing on an exclusive segment of the market (niche). For long term maintenance of competitive advantage, a firm must ensure that its methods cannot be duplicated or imitated. This requires constant analysis and regular reinvention of competitive strategies.
Studying your market will give you insight as to how you can make your business more appealing to people. Market research is more than just noticing trends in your customers' buying habits; it's discovering what motivates your customer to buy. Don't assume that you already know because you've been in this business for years. This study often unearths characteristics about your market that are hidden or new. It's best to discover these things before your competition.