Executive summary: This is the first section of your business plan, but it should be written last. The main purpose of an executive summary is to give an overview of your business, explaining all your main points in a few pages. Remember, your reader won’t necessarily be in the fashion industry, so write for a general audience and keep the jargon to a minimum.

Concept and market details: The actual business plan starts with an overall concept. What sets your fashion business apart from the competition? Do you cater to a specific audience or focus on a specific type of fashion? Who will your main clients be? Make sure you can back your claims with facts and figures from reliable sources, such as government agencies, universities, and business groups.

Market research: Next, give an overview of the market you’re entering, including your main competitors and how you plan to stand out. If you’re selling women’s clothing, what can you offer than no one else has? Maybe you’re catering to a specific sub-group, such as petite women, or a style that isn’t readily available, such as 70s fashion. Also include possible setbacks and how you can overcome them.

Methods and logistics: Investors will also want a step-by-step plan to making profits, from designing your store to launching your ad campaign. It also includes a detailed financial breakdown. At every step, make sure to factor in the costs, so the investor will know where you stand financially at any given point. Focus on solid steps (e.g. print out brochures, schedule seasonal sales) and explain how they will help your bottom line.

Profit projections: Numbers are the most important thing in a business plan. Offer estimates on startup costs, such as setting up the place and buying your first raw materials, as well as operating costs, including rent, staff wages, and marketing. Then give an estimate of your initial profit and how long it will take to earn it. Be realistic in your figures, and show your calculations whenever possible.

While entrepreneurs are engrossed in building the business, things such as market conditions and customer preferences may change, according to Mr. Berry. That’s why it’s important to take an occasional step back and look at the business from a wider perspective, he says.

There are several ways to do this—talking to individual customers (over lunch, even), doing an Internet search, or taking classes or workshops to bring a new angle into the way one runs business. The point, Mr. Berry says, is to work new initiatives into the business plan, with concrete steps and tangible goals.

In an article for The Entrepreneur, Mr. Berry offered a four-step guide to reworking one’s business plan and eventually increasing sales. First, he said, entrepreneurs should focus more on selling to existing customers rather than new ones. The example he gave was that of a computer store that called previous customers to remind them to upgrade their systems and offering special deals—at the same time clearing old stock and reinforcing good customer relations.

Next, Mr. Berry suggests rethinking pricing. It isn’t so much about how high or low they are, but how it fits with image and marketing, he says. Some people shy away from cheap products because they associate it with low quality, so lowering price may not always be a positive move.

The third step takes off on a related note: reviewing marketing messages, from content to delivery. This can mean using emerging channels such as social media, or reviving old ones such as email marketing and direct mail. In any case, Mr. Berry says, results must be measured in solid stats such as page views, ranking, or number of shares or retweets.

Finally, business owners must look into nearby markets, either by offering up something new to existing customers or selling existing items to a new demographic. According to Mr. Berry, this is more practical than coming up with a new product or service and finding new people to sell them to as well.

Mr. Berry wrapped up his article with a final tip: put everything in a business plan. This will force business owners to put everything down on paper, keep track of the results of implementation, and follow them up to see if any changes are needed.