It's important to illustrate strong market potential in size ($$$) and scope (long term growth.) Your business plan should make a compelling argument that illustrates a strong understanding of your operating environment, market trends, and how your business will strategize to use these trends to your advantage.
It's also important to not overlook the risk analysis section. Go a step beyond a simple SWOT analysis and describe your most primary risks, how you will mitigate them, and what your contingency plan is. If you don't have this section in your business plan, investors will undoubtedly grill you with questions on how you plan to deal with risk.
Keep terms consistent and be sure to PROVIDE CITATION for sources used in your market analysis. Yes, it can be a pain, but it goes a long way in showing the reader that you've done your homework.
Following a template is not a sure-fire way to write a success business plan. The outline posted here is a very good starting point--take it and adapt it, add sections, and remove sections to make the plan more relevant to your business and its operating environment. Above all, avoid using business plan software. In any business plan, your primary goals are to illustrate that you know what you're doing (strong team, market and competitive analysis sections), you know how to deal with risk, and that you are passionate about what you're doing. When writing for investors, try to avoid coming across as desperate--give the impression that whether or not you receive money from them, this is what you're doing, the investment would just make things a little easier.