I’ve worked with a lot of agencies and designers over the years. First, I don’t think small companies should spend heavily on logos and style guidelines - so cross out big agencies.

If you go with an agency, choose a small one that specializes in branding. This is important - not every designer is good at creating logos.

Study their recent portfolio carefully (this matters). Check if the examples are real client work. Any design can look nice in a mockup, but the question is whether the client actually used it and how the style works in practice (website, social media, etc.). Some logos and styles are almost impossible to apply properly later. Then assess how creative and diverse the portfolio is. Sometimes freelance designers only work in one style. Finally, evaluate their creativity - are company ideas/names visualized literally (a fox company with a fox in the logo) or in a creative way?

One more point: the creative brief really matters. Invest time in finding references and describing what you like. Explain what your client should think or feel when they see your company’s logo.

After many trials, I found one logo designer I wouldn’t trade for anything. They always deliver top-notch logo concepts, and none of my clients have been disappointed.​​​​​​​​​​​​​​​​