If you're thinking about starting a business, you likely already have an idea of what you want to sell, or at least the market you want to enter. Do a quick search for existing companies in your chosen industry. Learn what current brand leaders are doing and figure out how you can do it better. If you think your business can deliver something other companies don't (or deliver the same thing, but faster and cheaper), you've got a solid idea and are ready to create a business plan.
Double check yourself, before you double wreck yourself. Make sure everything you send to a company, whether a résumé, an email or a portfolio, is good to go. Double check your grammar and wording, and for God’s sake use spell check! This is especially important when it comes to the company’s name. Don’t spell their name wrong and be sure to type it how they type it (e.g. Problogger, not Pro Blogger).