-Never find those SEO companies that gives you guarantee Page 1 ranking because it's beyond their control as google can change the algorithm anytime.
-Find out how they build their links. Whether it's manually or using automated programs. What's their link building strategy for example tier building, local directories (Guessing it's a local company), social profiles etc..
-Find those that allow deposit and milestone payments. For example, you only pay each time when they help you reach a milestone.
-Find for those that offer onpage optimization ( good offsite links + bad onpage optimization = shit)
Anyone who specialize in SEO?, Anyone who specialize in SEO?