That’s like asking about the chicken and the egg!
You need a good branding strategy, but you also need to check your potential logo to see if it’s being used by someone else, and if it will pass the U.S. Patent and Trademark Office (USPTO) criteria for a trademarkable logo. So the answer is, you have to go back and forth until you find the right fit.
What does this entail? You may hire a branding firm or use marketing students at a local college to come up with a logo for your product. But before you start producing any packaging or do any marketing using that logo, you have to make sure you’re not infringing someone else’s trademark. You also have to make sure it’s the type of logo that the USPTO will approve. Just because you apply for a trademark doesn’t mean they’ll grant it! A trademark attorney can help you with this.
What trademarks won’t the USPTO grant? Names that are too close to already trademarked names, for one. For instance, the USPTO won’t grant a trademark for a soft drink called ‘Coca-Dola’ because it’s too close to Coca-Cola. It also won’t grant a trademark for a logo that’s too ‘descriptive’, meaning it tells what the product is. I know that sounds counter-intuitive, but everyone gets to use generic product descriptions and no one gets to own them. So that’s why a computer company is called Apple, a business machine company is called Xerox, tissues are called Kleenex, etc.
So how do you convey what your product is? You can add a picture as part of your logo, and that can be descriptive. We suggest you trademark your logo words, the picture, and the combination if you have the funds.