Get all your paper scanned and signed along with your partner's paperwork. Apply outside of the country. Upload all your docs through Thaievisa website (this includes your stamp entering whatever country you choose to apply from, hotel booking and transportation tickets), pay the embassy in person then wait. I went to Laos and I got the visa in less than 2 business days. Visa fee 2000 THB. Pretty quick despite the fact that you have to go to pay in person.