@Jimmy ***
Papers, witnesses, more papers, photos, more papers!
A ridiculous amount of papers. Marriage certificate, 400k in the bank, a preceding non-O visa, photos of you and the wife in and before the home, housebook, passport photos, everything with copies.
Then in the next month after your annual renewal stay near your home because they come to visit and inspect your home.
Immigration here (Sakon Nakhon) very much dislikes marriage visa and tries to push you towards retirement visa.