Can I extend my 30-day visa exemption in Thailand and what are my options for a longer stay?

Hi All

I'm a UK national in Thailand on a 30 day vusa exemption. I understand I may be able to extend this at thai immigration for another 30 days. Is this correct?

Ideally I am looking to stay for another 3-6 months so I take it a trip to the border is in order? There I can apply for 60 day tourist visa and extend again?

And repeat this process for 3 months?

Thanks