Their list is here and they tell you exactly what they need. You simply drop off your documents and passport to a window outside, from 9-11am. Then return the next business day to pick it up from 2-4pm.
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US does not like single asian women right now. Most of them are denied. Many of them overstayed in the US and have ruined it for others now. My wife's tourist visa was also denied twice before we were married. Now we are just doing the CR1 process.
I always go to Savannakhet. It has been the easiest for me and the consulate is easy. Also good food and coffee there. And they sell cheap, good Laos whiskey at the border before entering Thailand. I always get a bottle.
The motorcycle drivers here are like natural daredevils. I see them miss buses by an inch all the time. The way they are allowed to zip in-between traffic is nuts.
I told a Laos tuk tuk driver I only had baht. He said he can accept baht and give back change so we agreed on a price. When he dropped me off he suddenly had no change so I had to give him more money because I did not have smaller bills.