At Tandem.Buzz, we have access to many SEO tools, including SEMRush, Ahrefs, Moz, and more. When it comes to finding keywords, SEMRush seems to be the most user-friendly to me. If you don't work for an agency, a SEMRush (or other) account can definitely be considered costly. Remember, with an account, you might have tools and access to information not easily accessible for free. The keyword magic tool on SEMRush is easy to use, modify, and organize. Depending on the client I am working on and the keyword parameters they have set, I can do broad searches, search by volume or difficulty, and much more. Before investing in any tool, use a free trial. Though I already have my favorite, this will help you decide which program is best for you.