When starting a new business, some decisions may be very intentional while others are made hastily. To be sure, one approach isn't always better than the other. Some successful businesses are started more or less by accident. Perhaps a grandmother loves to cook for family and friends and is eventually encouraged to open "Grandma's Café."
That being said, there are risks involved in making hasty business decisions, particularly when it comes to brand signifiers. A carefully chosen and trademarked name can really increase a business' chances of success, while a generic-sounding name can lead to customer confusion and perhaps even legal issues.
Let's continue to use the example of "Grandma's Café." While such a name is quaint and wholesome, it is also rather generic. There's a good chance that other restaurants have already registered the trademark on that name or similar names. Therefore, you could be accused of trademark infringement if you don't research whether that name is available.
Even if you were the first to claim it, you might end up with unintentional copycats. As such, you may have to spend significant time and energy monitoring use of that name (or similar names) in the future by other restaurants to ensure that no one is infringing on your trademark.
Brand names are so powerful that they sometimes become synonymous with the product manufactured by a given brand. If someone said "please pass me a Kleenex," for instance, you'd almost certainly know they were asking for a tissue.
Because brand names have such power, choosing the name of your business should be an intentional decision supported by research. Once you have ensured that your brand name is unique, you should then file for trademark protection so that exclusive use of the name can be more easily enforced. An experienced business law attorney can help you with this or nearly any other legal process necessary to ensure the success of your business.