There are a few visa groups on facebook that Thai people share their processes, interviews, and queues. This one is the B1/B2 tourist visa queue in Chiang Mai posted yesterday. You can ask her to join the group. Most are in Thai, very useful and updated information.
What I normally do is separate 1, 2, 5, 10 coins then count 100 baht of each coins, put in a small plastic bag, write 100 baht on a paper and put it in the bag. I would go to local stores/restaurants/shops. No fees.
My boyfriend submitted the online application last week. Haven’t heard anything from the embassy yet. I wonder after submitting the application, did they send you an email to mail in the documents? TIA