Used an agency in Koh Samui...I sent my documents to them.
Partner had to travel to Bangkok though to personally hand in the paperwork which I didn't realise she had to do , but her and her girlfriend were happy to go on the trip,
....they offered the insurance when I opened my joint account too...they recommended I take out insurance for my partner...I politely said I didn't want to, it's part of the process I guess.