UK SEO Agencies: How Do You Find the Right One

Hi everyone, I have been researching SEO agencies in the UK to help improve my website’s search engine rankings. The options out there are overwhelming, and I am struggling to figure out how to differentiate between them. What should I look for when evaluating an SEO agency? Also, if anyone has worked with an SEO agency in the UK, what worked, what did not, and whether you saw real results. Looking forward to your insights.